[A clinical case of occupational allergy to piperacilline. A novel diagnostic method: basophil activation test (BAT)]. / Utilizzo del test di attivazione dei basofili (BAT) per la diagnosi di reazione allergica a piperacillina in ambito professionale: descrizione di un caso clinico.

BACKGROUND: Piperacillin, unlike other antibiotics, rarely causes immediate allergic reactions. Only two cases related to occupational exposure are reported in the literature. OBJECTIVES: Adoption of new methods for diagnosis of occupational allergy to drugs. METHODS: An atopic nurse, aged 30 years, was referred to our hospital for an allergic work-related reaction to piperacillin. The patient had suffered two successive episodes with immediate cutaneous reaction, angioedema and dyspnoea after preparing piperacillin. Almost four years previously she had suffered from similar symptoms after taking amoxicillin. She was submitted to a clinical examination and a routine allergic test, performing also specific IgE (Phadia Pharmacia ImmunoCap) and BAT (Basophil Activation Test) for Beta-lactam antibiotics. RESULTS: A positive response to piperacillin was observed in our case using BAT a new non-invasive and safe method, that proved useful for diagnosis of allergy. Moreover, we observed a change from an allergic reaction for therapeutic use of amoxicillin to a work-related adverse reaction to another beta-lactam, piperacillin. CONCLUSIONS: In previous clinical cases cutaneous and specific challenge tests were performed for diagnosis. At present, availability of an in vitro test, such as BAT may provide new diagnostic opportunities, and a useful tool for studying clinical cases other than, in perspective, monitoring exposed workers. Preventive measures were taken in the workplace to lower the risk of sensitization and allergic response. The nurse was transferred to a well controlled job.

Clinicoprognostic implications of increased serum levels of vascular endothelial growth factor and basic fibroblastic growth factor in early B-cell chronic lymphocytic leukaemia.

To assess the relative merit of increased serum levels of vascular endothelial growth factor and basic fibroblastic growth factor in predicting the risk of disease progression of patients with early B-cell chronic lymphocytic leukaemia we analyzed 81 Binet stage A patients whose sera were taken at the time of diagnosis and evaluated for the presence of vascular endothelial growth factor and basic fibroblast growth factor using an enzyme-linked immunosorbent assay. Serum levels of vascular endothelial growth factor positively correlated with Rai sub-stages (P=0.03), peripheral blood lymphocytosis (P=0.03), bone marrow histology (P=0.04) and beta2-microglobulin (beta2-m) (P=0.006). When dealing with basic fibroblast growth factor only a correlation with Rai sub-stages (P=0.02) could be found. Different cut-offs set on the basis of a stratification in quartiles, failed to demonstrate any correlation between serum levels of basic fibroblast growth factor and disease progression. In contrast, patients with increased serum levels of vascular endothelial growth factor (above median value, 203 pg ml(-1)) had a three times increased risk of disease progression, although, in multivariate analysis only Rai sub-stages (P=0.0001) and lymphocyte doubling time (P=0.002) retained their prognostic significance. Low levels of vascular endothelial growth factor were indicative of good clinical outcome in the subgroup of patients with either low (P=0.02) or high (P=0.03) beta2-m concentration. Finally, the highest prognostic power was obtained when serum vascular endothelial growth factor and beta2-m were examined in combination. Median of progression-free survival of patients who had both serum vascular endothelial growth factor and beta2-m higher than median value was only 13 months, in contrast median progression-free survival of patients with one marker increased (i.e. above the 50th percentile) was 40 months. Patients with both markers below the median experienced the best clinical outcome (median progression-free survival not reached at 40 months). In conclusion, serum levels of either vascular endothelial growth factor or basic fibroblast growth factor are high in patients with early chronic lymphocytic leukaemia, however, only vascular endothelial growth factor predicts behaviour of disease and helps to refine the prognosis of stage A patients.

Prospects for the use of antioxidant therapy in hypertension.

The purpose of this review is to examine the indications and contraindications of antioxidant therapy in arterial hypertension. It has been suggested that oxidative stress plays a role in hypertension, increasing pressure values and leading to complications. Oxidative stress, at present, appears as one of several metabolic abnormalities described in essential hypertension. It is still uncertain whether this abnormality is primary or secondary; in any case, measurement of the main oxidant and antioxidant activities in plasma and blood cells may be useful in order to recognize and monitor oxidative stress. Antioxidant therapy could be useful to counteract the effects of oxidative stress on blood vessels, arterial pressure and low-density lipoproteins. Although antioxidant therapy with drugs or physiological substances in hypertensive subjects has been examined in some clinical trials, these experimental observations do not appear sufficient to draw definitive conclusions because long-term randomized, controlled studies do not exist. At present, it seems appropriate to propose some dietary recommendations which, apart from their antioxidant properties, are useful and do not have untoward effects. The safest approach to treat or to prevent oxidative stress consists of a diet that includes foods with a high antioxidant content (i.e. vitamins C and E and flavonoids). This diet consists fundamentally of fruits, vegetables and grains. Moreover it seems useful to use antihypertensive drugs that are able to decrease oxidative stress. The addition of physiologic antioxidant substances should be considered only in hypertensive subjects with a marked increase in oxidant or decrease in antioxidant factors. Indeed reactive oxygen species play a pivotal role in many physiological reactions, and their excessive inhibition could be dangerous. Further controlled, randomized long-term trials with antioxidants in hypertension are necessary to establish the efficacy and tolerability of antioxidants in the adjuvant therapy of hypertension.

Timing of breast cancer surgery within the menstrual cycle: tumor proliferative activity, receptor status and short-term clinical outcome.

We verified the variations of primary tumour steroid receptor status and proliferative activity at different times and phases (follicular vs luteal) of the menstrual cycle and their relationship with short clinical outcome in a cohort of 248 N- breast cancer patients. Steroid receptor content (ER and PgR) was evaluated by DCC assay and proliferative activity by 3H-Thymidine autoradiographic assay (TLI). Median age was 44 years, 60% of tumors were T1, and cytohistological grade was G1-2 in 54% of cases. At surgery, 57% were in the luteal phase while 43% were in the follicular phase. No significant variations were found in mean TLI or ER and PgR characteristics of the primary tumors surgically treated in different periods of the menstrual cycle; however, the ER level resulted significantly higher in 4th with respect to the 3rd week of menstrual cycle, while PgR level was higher in PgR+ cases treated during the 3rd week. The number of relapses and disease-free survival curves after 36 months median follow-up did not differ significantly for patients treated in different periods of the menstrual cycle (12% and 9% of disease relapses in luteal and follicular phases; p=n.s.). We can conclude, therefore, that TLI, ER and PgR expressions could vary significantly during menstrual cycle only in certain specific tumor subgroups.

Immunohistochemical detection of high-affinity nerve growth factor receptor in neuroblastoma.

High levels of mRNA (as assessed by northern blot) for the high-affinity nerve growth factor receptor (p140TRK) are predictive of favourable outcome in neuroblastoma. The feasibility of determining p140trk on frozen sections using a recently developed monoclonal antibody was evaluated, and immunohistochemical findings were compared to those obtained from northern blot analysis. Primary tumour samples from 28 untreated patients were quick frozen and an indirect immunofluorescence assay was performed on 4-microns acetone-fixed cryostat sections. 9 cases were positive with immunohistochemistry, and these were among the 15 cases also positive by northern blot. None of the cases negative by northern blot were positive with immunohistochemistry. The concordance rate was 79% (P < 0.03), with a sensitivity of 60% and a specificity of 100%. Immunohistochemistry can thus be rather reliable for assessing p140trk expression, even when only very small amounts of tissue are available, such as with needle biopsy.

Immunotoxins to the HER-2 oncogene product: functional and ultrastructural analysis of their cytotoxic activity.

Two immunotoxins were prepared using monoclonal antibodies (mAb) directed towards two distinct epitopes of the gp185HER-2 extracellular domain, and the type I ribosome inactivating protein (RIP) plant toxin saporin 6. Cell protein synthesis inhibition assay reveals that the immunotoxins display a potent and specific cytotoxicity that is characterized by a slow rate, since the time required to inhibit incorporation of radiolabeled leucine completely ranges from 36 h to 60 h depending on the target cell line and the immunotoxin. Because this feature may hamper the immunotherapeutic use of these conjugates we analysed this further by studying the early phases of internalization of immunotoxins by immunoelectron microscopy. The results of this study have demonstrated that the distribution pattern of the immunotoxins and of the unconjugated mAb over the cell surface overlaps. Similarly the mAb and immunotoxins are internalized into the cell by two different pathways: via clathrin-coated pits or via smaller uncoated pits and vesicles. A higher degree of internalization is achieved when the two immunotoxins are used in combination. Unlike the slow kinetics of cell intoxication the process of immunotoxin endocytosis is characterized by a rapid rate of internalization (above 40% at 5 min in the SK-BR-3 cell line). Although these findings provide no clue to explain the mechanisms of the slow rate of cytotoxicity of the two immunotoxins their rapid internalization indicates that these reagents can be exploited in immunotherapeutic approaches to gp185HER-2-expressing malignancies.

Expression of gp185HER-2 in human cutaneous melanoma: implications for experimental immunotherapeutics.

Over-expression of the HER-2 oncogene correlates with poor prognosis in breast and ovarian carcinomas. Using a sensitive immunohistochemical assay, we have detected low levels of gp185HER-2 in intradermal nevi (78%) and in primary (75%) and metastatic melanomas (58%). The HER-2 gene product expressed by cultured melanoma cells had the expected molecular weight, but no levels of tyrosine phosphorylation could be detected. Consistently, we were unable to inhibit in vitro growth of melanoma cells with an anti-gp 185HER-2 MAb, in conditions in which the growth of SKBr-3 breast-carcinoma cells was severely impaired. However, immunotoxins to gp 185HER-2 were able to kill gp185HER-2-positive melanoma cells. These data indicate that low levels of gp185HER-2 are expressed by the melanocyte lineage, with no correlation with transformation or tumor progression. Nevertheless, gp185HER-2 appears a suitable target for immunotherapy of cutaneous melanoma.

Shc products are substrates of erbB-2 kinase.

The shc genes encodes three widely expressed proteins of 46, 52 and 66 kDa. Overexpression of p46shc and p52shc in NIH3T3 fibroblasts induces a tumorigenic phenotype. Shc products are phosphorylated on tyrosine by the activated epidermal growth factor receptor (EGFR) and become physically associated with EGFR via their SH2 domain. Thus Shc oncoproteins may play a role in mitogenic signal transduction. Here we report that Shc products are substrates also of the erbB-2 kinase and form complexes with the erbB-2 product in intact cells. In vitro, the bacterially expressed Shc SH2 domain is sufficient to reconstitute the high affinity Shc/erbB-2 interaction. The erbB-2 region required for Shc binding was narrowed down to the most COOH-terminal 179 residues of gp185erbB-2; within this region, phosphorylation of one or more of the erbB-2 autophosphorylation sites is required for Shc/gp185erbB-2 complex formation as well as optimal phosphorylation of Shc products by the erbB-2 kinase. Thus, Shc proteins may play a role in signal transduction by gp185erbB-2.

Characterization of cytotoxic activity of saporin anti-gp185/HER-2 immunotoxins.

The oncogene HER-2/neu encodes a trans-membrane receptor of 185 kDa with tyrosine-kinase activity. Over-expression of this molecule has been reported in a significant proportion of human breast and ovarian carcinomas, characterized by a poor clinical prognosis. Two monoclonal antibodies (MAbs), recognizing distinct epitopes of the gp 185 extracellular domain, have been utilized in the present study for the production of immunotoxins (ITs) by conjugation to the type-1 RIP (ribosome-inactivating protein) plant toxin saporin 6 (SAP). These ITs have been shown to retain tumor-specificity and specifically to inhibit protein synthesis in the gp185HER-2(+) SK-BR-3 breast-carcinoma cell line with IC50 values lower then 1 nM. Kinetics of the cytotoxic activity of the ITs are characterized by a slow rate, since incubation times ranging from 24 to 60 hr, depending on the different degree of expression of the receptor, are required to determine > 90% inhibition in the incorporation of radiolabeled leucine. However, the cytotoxic activity of these ITs, as evaluated by a more sensitive clonogenic assay, appears highly potent, since we have observed that 3 to 4 logs of cells are killed upon exposure to the ITs for short times at concentrations ranging from 1 to 5 x 10(-8) M.

Production and characterization of murine mAbs to the extracellular domain of human neu oncogene product GP185HER2.

The oncogene HER-2/neu encodes a transmembrane glycoprotein of 185 kDa (gp185HER-2) with tyrosine-kinase activity. Gene amplification and high levels of expression of gp185HER-2 have been found to correlate with poor clinical outcome in breast and ovarian carcinomas. Employing a somatic cell hybrid fusion protocol, which yields a high frequency production of hybridomas, we have analyzed the extent of the murine immune response to the gp 185 extracellular domain. In a single fusion experiment, using as immunogen NIH 3T3 cells expressing high levels of a transfected human HER-2 gene, we have generated mAbs, mainly of IgG1 isotype, displaying high affinity (10(7)-10(10) mol/L) to gp 185. Analysis of the epitope specificity has allowed the identification of five distinct groups of spatially related epitopes, each provided with different immunodominancy, and all resistant to formalin fixation. The use of inhibitor of N-linked glycosylation tunicamicyn has demonstrated that the mAbs bind to epitopes localized in the protein core of gp185HER-2. Because recent reports have shown that gp185HER-2 has a restricted expression in normal tissues and is homogenously detectable in metastatic foci of gp 185 + primary tumors, antibodies to this macromolecule, in addition to their prognostic value, may represent reagents for in vitro and in vivo diagnostic applications, as well as for the development of therapeutic strategies.

Use of MoAb D612 in combination with a panel of MoAb for the immunocytochemical identification of metastases from colon-rectum carcinoma.

During the course of colon-rectum tumours a number of clinical events may occur in which conventional cytopathology can provide only a partial contribution to the definition of a differential diagnosis, i.e. effusions, distant recurrences and second neoplasias. In the present study we have evaluated whether monoclonal antibody (MoAb) D612, recognising a colon-rectum associated antigen, can be used in this context. To this end, MoAb D612 was employed in combination with a panel of MoAb of well defined tumour specificity in immunocytochemical tests. The immunocytochemical findings obtained were compared with the histological and clinical diagnosis. Of 62 effusions and 40 fine needle aspirates studied, MoAb D612 reactivity correlated with the correct diagnosis in 92.8% of the instances. These results indicate that this reagent may help to improve the current cytopathological diagnosis of colon-rectum tumours by identifying the colonic origin of metastases in patients with unknown primary tumour, differentiating ovarian carcinoma from colon metastases to the ovaries and establishing the presence of a second neoplasia in patients with a previous history other than colon carcinoma.