First-line immunotherapy for lung cancer with MET exon 14 skipping and the relevance of TP53 mutations

BACKGROUND

The efficacy of checkpoint inhibitors for non-small cell lung cancer (NSCLC) with MET exon 14 skipping (METΔ14ex) remains controversial.

MATERIALS AND METHODS

110 consecutive METΔ14ex NSCLC patients receiving first-line chemotherapy (CHT) and/or immunotherapy (IO) in 10 German centers between 2016-2022 were analyzed.

RESULTS

Combined CHT-IO was given to 35/110 (32%) patients, IO alone to 43/110 (39%), and CHT to 32/110 (29%) upfront. Compared to CHT, CHT-IO showed longer progression-free survival (median PFS 6 vs. 2.5 months, p = 0.004), more objective responses (ORR 49% vs. 28%, p = 0.086) and numerically longer overall survival (OS 16 vs. 10 months, p = 0.240). For IO monotherapy, OS (14 vs. 16 months) and duration of response (26 vs. 22 months) were comparable to those of CHT-IO. Primary progressive disease (PD) was more frequent with IO compared to CHT-IO (13/43 vs. 3/35, p = 0.018), particularly for never-smokers (p = 0.041). Higher PD-L1 TPS were not associated with better IO outcomes, but TP53 mutated tumors showed numerically improved ORR (56% vs. 32%, p = 0.088) and PFS (6 vs. 3 months, p = 0.160), as well as longer OS in multivariable analysis (HR=0.54, p = 0.034) compared to their wild-type counterparts. Any second-line treatment was administered to 35/75 (47%) patients, with longer survival for capmatinib or tepotinib compared to crizotinib (PFS 10 vs. 3 months, p = 0.013; OS 16 vs. 13 months, p = 0.270).

CONCLUSION

CHT-IO is superior to CHT, and IO alone also effective for METΔ14ex NSCLC, especially in the presence of TP53 mutations and independent of PD-L1 expression, but never-smokers are at higher risk of primary PD.

Pembrolizumab Alone or With Chemotherapy for 70+ Year-Old Lung Cancer Patients: A Retrospective Study

OBJECTIVE

First-line pembrolizumab alone, as approved for PD-L1 ≥50%, or with chemotherapy was analyzed in older non-small-cell lung cancer (NSCLC) patients, for whom evidence is scarce.

MATERIALS AND METHODS

A total of 156 consecutive ≥70 year-old patients treated between January 2016 and May 2021 were retrospectively analyzed. Tumor progression was verified through radiologic review, while toxicity was captured from records.

RESULTS

Pembrolizumab plus chemotherapy (n = 95) caused higher rates of adverse events (91% vs. 51%, P < .001), treatment discontinuation (37% vs. 21%, P = .034), and hospitalization (56% vs. 23%, P < .001), but similar rates of immune-related adverse events (irAEs, mean 35%, P = .998) compared to pembrolizumab monotherapy (n = 61). Progression-free (PFS) and overall survival (OS) were similar between the 2 groups (7 vs. 8 months, and 16 vs. 14 months in median, P > .25). Occurrence of irAEs was associated with longer survival in a 12-week landmark analysis (median PFS 11 vs. 5 months, hazard ratio [HR] 0.51, P = .001; median OS 33 vs. 10 months, HR 0.46, P < .001), but occurrence of other AEs not (both P > .35). A worse ECOG performance status (PS) ≥2, presence of brain metastases at diagnosis, squamous histology and lack of tumor PD-L1 expression were independent predictors of shorter PFS and OS in multivariable analysis (HR 1.6-3.9 for PFS and OS, all P < .05).

CONCLUSION

Chemoimmunotherapy increases the rate of adverse events and hospitalization without prolonging PFS or OS in newly diagnosed NSCLC patients aged 70 years or older compared to pembrolizumab monotherapy. ECOG PS 2, presence of brain metastases at diagnosis, squamous histology and PD-L1 negativity are associated with poor outcome.

Real-world data for precision cancer medicine-A European perspective

Leveraging real-world data (RWD) for drug access is necessary to overcome a key challenge of modern precision oncology: tackling numerous low-prevalence oncogenic mutations across cancers. Withholding a potentially active medication in patients with rare mutations for the sake of control chemotherapy or "best" supportive care is neither practicable nor ethically justifiable anymore, particularly as RWD could meanwhile be used instead, according to scientific principles outlined by the US Food and Drug Administration, European Medicines Agency and other stakeholders. However, practical implementation varies, with occasionally opposite recommendations based on the same evidence in different countries. In the face of growing need for precision drugs, more transparency of evaluation, a priori availability of guidance for the academia and industry, as well as a harmonized framework for health technology assessment across the European Union (EU) are imperative. These could in turn trigger infrastructural changes in national and pan-European registries, cancer management guidelines (e.g., frequency of routine radiologic restaging, inclusion of patient-reported outcomes), and the health data space, to ensure conformity with declared standards and facilitate extraction of RWD sets (including patient-level data) suitable for approval and pricing with minimal effort. For an EU-wide unification of precision cancer medicine, collective negotiation of drug supply contracts and funding solidarity would additionally be required to handle the financial burden. According to experience from pivotal European programs, off-label use could potentially also be harmonized across EU-states to accelerate availability of novel drugs, streamline collection of valuable RWD, and mitigate related costs through wider partnerships with pharmaceutical companies.

Recent advances in small cell lung cancer: the future is now?

Small cell lung cancer is a relevant clinical issue as it is a highly malignant cancer, often diagnosed in advanced stage. Similarly to non-small cell lung cancer, tobacco smoking is currently the main risk factor. Its incidence, at least in males, has declined over the past decades, due to the worldwide decreased percentage of active smokers. The typical small cells of this tumor type are characterized by a high Proliferation Index, chromosomal deletions such as 3p(14-23) involving the tumor-suppressor gene FHIT, alterations of the MYC or Notch family proteins and the frequent expression of neuroendocrine markers. The combination of thoracic radiotherapy and chemotherapy is the standard treatment for limited stage disease, while platinum-based chemotherapy is the most effective choice for extensive stage disease. Unfortunately, whatever chemotherapy is used, the results are disappointing. No regimen has proved to be effective in the long run, indeed small cell lung cancer rapidly progresses after a frequent initial strong response, and the mortality rate remains still high. The advent of immunotherapy is actually changing the landscape in oncology. As well as in other cancers, recent trials have demonstrated the efficacy of the combination of immune checkpoint inhibitors and chemotherapy, opening new perspectives for the future of our patients.

Major clinical benefit from adjuvant chemotherapy for stage II–III non-small cell lung cancer patients aged 75 years or older: a propensity score-matched analysis

Background

Data are currently insufficient to support the use of adjuvant chemotherapy (ACT) after surgical resection for stage II or III non-small cell lung cancer (NSCLC) in patients aged ≥ 75 years. In this study we evaluated efficacy and safety profile of ACT in this population.

Methods

We retrospectively evaluated 140 patients ≥ 75 years who underwent curative surgical resection for stage II–III NSCLC from 2010 to 2018 with an indication to ACT according to current guidelines. A propensity score-matched analysis was performed to avoid cofounding biases.

Results

Thirty of 140 patients (21%) received ACT. Most patients (n = 24, 80%) received carboplatin in combination with vinorelbine, while 5 patients (17%) received cisplatin plus vinorelbine and one patient (3%) carboplatin plus gemcitabine. The occurrence of adverse events led to treatment discontinuation in 8 (27%) cases, while 19 (63%) patients completed 4 chemotherapy cycles. Common reported adverse events with ACT were anemia (n = 20, 67%), neutropenia (n = 18, 60%), thrombocytopenia (n = 9, 30%), renal impairment (n = 4, 13%) and transaminase elevation (n = 4, 13%). No toxic deaths occurred. The median follow-up was 67 months (IQR: 53–87). ACT was associated with a significant benefit in both relapse-free survival (median 36 vs. 18.5 months, p = 0.049) and overall survival (median not reached [NR] vs. 33.5 months, p = 0.023) in a propensity score-matched analysis which controlled for cofounders.

Conclusion

ACT confers a survival benefit after curative resection of stage II–III NSCLC in selected patients aged 75 years or older with a manageable toxicity profile.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02043-6.

Impact of molecular alterations on quality of life and prognostic understanding over time in patients with incurable lung cancer: a multicenter, longitudinal, prospective cohort study

PURPOSE

The purpose of this study is to investigate changes over time in quality of life (QoL) in incurable lung cancer patients and the impact of determinants like molecular alterations (MA).

METHODS

In a prospective, longitudinal, multicentric study, we assessed QoL, symptom burden, psychological distress, unmet needs, and prognostic understanding of patients diagnosed with incurable lung cancer at the time of the diagnosis (T0) and after 3 (T1), 6 (T2) and 12 months (T3) using validated questionnaires like FACT-L, National Comprehensive Cancer Network (NCCN) Distress Thermometer (DT), PHQ-4, SCNS-SF-34, and SEIQoL.

RESULTS

Two hundred seventeen patients were enrolled, 22 (10%) with reported MA. QoL scores improved over time, with a significant trend for DT, PHQ-4, and SCNS-SF-34. Significant determinants for stable or improving scores over time were survival > 6 months, performance status at the time of diagnosis, and presence of MA. Patients with MA showed better QoL scores (FACT-L at T1 104.4 vs 86.3; at T2 107.5 vs 90.0; at T3 100.9 vs 92.8) and lower psychological distress (NCCN DT at T1 3.3 vs 5; at T2 2.7 vs 4.5; at T3 3.7 vs 4.5; PHQ-4 at T1 2.3 vs 4.1; at T2 1.7 vs 3.6; at T3 2.2 vs 3.6), but also a worsening of the scores at 1 year and a higher percentage of inaccurate prognostic understanding (27 vs 17%) compared to patients without MA.

CONCLUSION

Patients with tumors harboring MA are at risk of QoL deterioration during the course of the disease. Physicians should adapt their communication strategies in order to maintain or improve QoL.

Combination of Crizotinib and Osimertinib in T790M+ EGFR-Mutant Non-Small Cell Lung Cancer with Emerging MET Amplification Post-Osimertinib Progression in a 10-Year Survivor: A Case Report

Tyrosine kinase inhibitors (TKIs) represent the standard treatment for patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. The duration of the response is, however, limited in time owing to the development of resistance mechanisms to both first- and second-generation agents such as MET oncogene amplification. This report describes the successful results obtained with the combination of the third-generation TKI osimertinib with the multitargeted TKI and MET inhibitor crizotinib in a patient with EGFR-mutant NSCLC with emerging MET amplification with a tolerable toxicity profile.

Recent advances in small cell lung cancer: the future is now?

Small cell lung cancer is a relevant clinical issue as it is a highly malignant cancer, often diagnosed in advanced stage. Similarly to non-small cell lung cancer, tobacco smoking is currently the main risk factor. Its incidence, at least in males, has declined over the past decades, due to the worldwide decreased percentage of active smokers. The typical small cells of this tumor type are characterized by a high proliferation index, chromosomal deletions such as 3p(14-23) involving the tumor-suppressor gene FHIT, alterations of the MYC or Notch family proteins and the frequent expression of neuroendocrine markers. The combination of thoracic radiotherapy and chemotherapy is the standard treatment for limited stage disease, while platinum-based chemotherapy is the most effective choice for extensive stage disease. Unfortunately, whatever chemotherapy is used, the results are disappointing. No regimen has proved to be effective in the long run, indeed small cell lung cancer rapidly progresses after a frequent initial strong response, and the mortality rate remains still high. The advent of immunotherapy is actually changing the landscape in oncology. As well as in other cancers, recent trials have demonstrated the efficacy of the combination of immune checkpoint inhibitors and chemotherapy, opening new perspectives for the future of our patients.

Autoimmune-related encephalitis during treatment with nivolumab for advanced head and neck cancer: a case report

INTRODUCTION

Head and neck cancer represents a variety of tumors involving different organs in the cervical district, burdened by poor prognosis when diagnosed in an advanced stage. Immunotherapy with both anti-PD-1 nivolumab and pembrolizumab has the aim of increasing overall survival for patients with this malignancy. We report the first case of immune-related encephalitis caused by nivolumab in this setting of disease and present a brief review of the literature.

CASE DESCRIPTION

A 60-year-old woman had been treated with concomitant chemoradiotherapy for a locally advanced human papillomavirus-negative squamous cell carcinoma of the tonsil. After local recurrence, she was treated with platinum-based first-line chemotherapy, followed by nivolumab at further progression within 6 months. Nivolumab was administered for 19 weeks, then discontinued due to the occurrence of immune-related hypothyroidism and grade 2 diarrhea. A month after the onset of the endocrinopathy, the patient also developed steroid-responsive encephalitis, considered as a consequence of anti-PD-1 therapy. One year after discontinuation of immunotherapy, toxicities have resolved and the patient is maintaining a complete radiologic response.

CONCLUSIONS

Immunotherapy is a relatively new and promising therapy in the field of oncology. Its mechanism of action, which aims to stimulate the immune system against cancer cells, is not comparable to systemic and cytotoxic chemotherapy, which directly attacks and destroys malignant cells. Despite these differences, immunotherapy is not to be considered free from side effects, sometimes life-threatening.

Durvalumab in frail and elderly patients with stage four non-small cell lung cancer: Study protocol of the randomized phase II DURATION trial

Background

Elderly patients represent a major fraction of non-small cell lung cancer (NSCLC) patients in routine clinical practice, but they are still underrepresented in clinical trials. In particular, data regarding efficacy and safety in frail or elderly patients with respect to immunotherapy are lacking. Importantly, immunosenescence in elderly patients might interfere with activities of immune-modulating drugs such as PD-1/PD-L1 inhibitors. Thus, there is an urgent need to assess safety and efficacy of such inhibitors in this group.

Methods/design

This prospective, open label, treatment stratified, randomized phase II study will enroll 200 patients with stage IV NSCLC amenable at least to single-agent chemotherapy (CT). Eligible patients must be aged 70 years or older and/or “frail” (Charlson Comorbidity Index > 1) or have a restricted performance status (Eastern Cooperative Oncology Group, ECOG > 1).

Patients are stratified according to modified Cancer and Age Research Group (CARG) score: “fit” patients are allocated to combination CT (carboplatin/nab-paclitaxel) and “less fit” patients receive single-agent CT (gemcitabine or vinorelbine). After allocation to strata, patients are randomized 1:1 to receive either four cycles of CT or two cycles of CT followed by two cycles of durvalumab and subsequent maintenance treatment with durvalumab every 4 weeks.

The primary endpoint is the rate of treatment-related grade III/IV adverse events (Common Terminology Criteria for Adverse Events (CTCAE) V4.03). As secondary endpoints, progression-free survival (PFS) according to Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1, response rate (RR), overall survival (OS), descriptive subgroup analyses according to PD-L1 expression, and quality of life are addressed. Geriatric screening assessments and functional tests will be performed to complete the phenotyping of a potential “frail” and “elderly” patient cohort. The trial is accompanied by a biomaterial repository to explore potential biomarkers.

Discussion

The DURATION trial will prospectively investigate the safety and tolerability of anti-PD-L1 treatment with durvalumab after chemotherapy in elderly and frail patients and thereby provide new insights into the effect of PD-L1 blockade and the impact of immunosenescence in this cohort of patients.

Trial registration

ClinicalTrials.gov, NCT03345810; initially registered on 17 November 2017.

Eudra-CT, 2016–003963-20; initially registered on 3 January 2017.

Long-term disease-free survival in surgically-resected oral tongue cancer: a 10-year retrospective study

Early and loco-regionally advanced oral tongue squamous cell carcinoma (OTSCC) can be treated by surgery alone or followed by adjuvant radiotherapy or chemoradiotherapy. Nevertheless, up to 40% of patients develop tumour relapse. The aim of our study is to investigate the clinical and pathological features associated with reduced disease-free survival (DFS) in a cohort of surgically-resected OTSCC patients. One hundred and six patients surgically resected for OTSCC were retrospectively identified from clinical records. DFS was calculated according to the Kaplan–Meier method and differences between variables were assessed with Log-Rank test. A multivariable Cox regression model was used to analyse the impact of different prognostic factors on DFS. After a median of follow-up of 8.9 years, 22 events, including 11 deaths, were observed. Overall, the 5-year DFS-rate was 87.4%. The presence of extra-nodal extension (p = 0.023) and perineural invasion (p = 0.003) were significantly correlated with shorter DFS (in univariate analysis). In multivariable analysis, extra-nodal extension and perineural invasion confirmed their role as independent prognostic factors associated with an increased risk of disease recurrence [hazard ratio (HR) 2.87, 95% CI 1.11-7.42, p = 0.03; HR 3.85, 95% CI 1.49-9.96, p = 0.006, respectively]. p16 and p53 expressions in tumour cells were detected in 12% (n = 9) and 46% (n = 40) of cases, respectively. No differences in DFS were observed between p16+ and p16- (p = 0.125) and between p53+ and p53- tumours (p = 0.213). In conclusion, radical surgery, eventually followed by adjuvant radiotherapy or chemo-radiotherapy, can achieve high cure rates in OTSCC. After long-term follow-up, perineural invasion and extra-nodal extension confirmed their role as prognostic factors associated with reduced DFS in OTSCC patients.

PTX3 Intercepts Vascular Inflammation in Systemic Immune-Mediated Diseases

PTX3 is a prototypic soluble pattern recognition receptor, expressed at sites of inflammation and involved in regulation of the tissue homeostasis. PTX3 systemic levels increase in many (but not all) immune-mediated inflammatory conditions. Research on PTX3 as a biomarker has so far focused on single diseases. Here, we performed a multi-group comparative study with the aim of identifying clinical and pathophysiological phenotypes associated with PTX3 release. PTX3 concentration was measured by ELISA in the plasma of 366 subjects, including 96 patients with giant cell arteritis (GCA), 42 with Takayasu's arteritis (TA), 10 with polymyalgia rheumatica (PMR), 63 with ANCA-associated systemic small vessel vasculitides (AAV), 55 with systemic lupus erythematosus (SLE), 21 with rheumatoid arthritis (RA) and 79 healthy controls (HC). Patients with SLE, AAV, TA and GCA, but not patients with RA and PMR, had higher PTX3 levels than HC. PTX3 concentration correlated with disease activity, acute phase reactants and prednisone dose. It was higher in females, in patients with recent-onset disease and in those with previous or current active vasculitis at univariate analysis. Active small- or large- vessel vasculitis were the main independent variables influencing PTX3 levels at multivariate analysis. High levels of PTX3 in the blood can contribute to identify an increased risk of vascular involvement in patients with systemic immune-mediated diseases.

Nutritional and functional status impairments to predict early death in elderly patients with advanced non-small-cell lung cancer (NSCLC)

e20600

Background: Early death for some patients can be explained by direct effect of tumor or can be secondary to cancer treatment.As for many patients it is not fully predictable, the factors influencing and determining early death in older individuals receiving chemotherapy for advanced NSCLC were analyzed. Methods: Advanced NSCLC patients, > 70 years, ECOG performance status 0-1, treatment naïve, stage IIIB and IV, EGFR and ALK negative, were eligible. Geriatric assessment was performed at baseline and included: Performance status, ADLs, IADLs, CIRSG score and index, Mini Nutritional Assessment (MNA), Mini Mental State Evaluation (MMSE), educational and social status assessment, Geriatric Depression Scale (GDS).All patients, according to their classification in frail, vulnerable or fit, received best supportive care, monotherapy or doublet chemotherapy.For all patients data on number of cycles, response, discontinuation of treatment, dose reductions, grade 3/4 hematological and non-hematological toxicity were recorded. Patients who died within 90 days of diagnosis were considered.A descriptive statistic was calculated and a logistic regression analysis with the assessment of factors and covariates influencing early death events was performed. Results: From June 2010 to March 2016, 204 patients were assigned to platinum-based doublet (n = 73) or single-agent chemotherapy (n = 131).Median age was 75, 72% were males, 52% had non-squamous histology. Median number of cycles was 4, and was 3 for comorbidities. IADLs were impaired in 42%, ADLs in 6%,MNA in 15% and MMSE 10% of patients.Sixty-eight percent of patients were dead at the time of the analysis; 24% (49/204) had partial response, 25% (51/204) had stable disease and 51% (104/204) had progressive disease.At multivariate logistic model IADLs (p 0.001, OR 1.4 95%CI 0.4-1.6),MNA (p 0.001, OR 1.35 CI 0.1-1.35) and polypharmacy (p 0.008, OR 1.2 CI 1-1.4) were significantly associated with the occurrence of early death. Conclusions: The identification and management of patients with nutritional and functional impairments could help oncologists to reduce the risk of early death during chemotherapy for advanced NSCLC.

Plasma levels of M-CSF are increased in ANCA-associated vasculitides with active nephritis

Anti-Neutrophil Cytoplasmic Antibodies (ANCA)-associated vasculitides (AAV) are characterized by small vessel injury and in some cases granulomatous lesions and glomerular inflammation. The pathogenic bases of these clinical phenotypes are incompletely understood, but evidence from patients with AAV and other inflammatory diseases suggest a role for monocyte/macrophages in the perpetuation of tissue injury. Macrophage colony stimulating factor (M-CSF) is a promoter of monocyte recruitment and macrophage proliferation, involved in mesangial cell proliferation and experimental nephritis development. Serum concentrations of M-CSF mark and herald the onset of lupus nephritis. Plasma samples from 29 patients with AAV (18 granulomatosis with polyangiitis, GPA, 6 eosinophilic granulomatosis with polyangiitis, EGPA, and 5 microscopic polyangiitis, MPA) and from 10 healthy controls were collected together with clinical data. Patients with AAV had higher levels of M-CSF when compared to controls. M-CSF levels correlated positively with the BVAS, serum C-reactive protein and erythrocyte sedimentation rate, while haemoglobin correlated inversely with M-CSF. Patients with active renal disease had significantly higher levels of M-CSF when compared to the other subgroups. M-CSF levels did not differ between ANCA subserotypes and were not associated with the involvement of other organs. In conclusion, M-CSF is higher in patients with AAV and active nephritis and could contribute to the pathogenesis of these diseases. In addition, M-CSF could behave as a useful marker of renal involvement in AAV.

National surveillance capacity of water-related diseases in the WHO European region

Water-related diseases continue to cause a high burden of mortality and morbidity in the countries of the European Region. Parties to the Protocol on Water and Health are committed to the sustainable use of water resources, the provision of safe drinking water and adequate sanitation to all people of the European Region, and to the reduction of the burden of water-related diseases. A specialized Task Force is implementing a work plan aimed at strengthening the capacity for water-related disease surveillance, outbreak detection and contingency planning. Parties to the Protocol are obliged to set targets, and report on progress on water-related disease surveillance. The present paper aims to provide a baseline assessment of national capacities for water-related disease surveillance on the basis of the replies to a questionnaire. This was prepared in English and Russian and administered to 53 countries, 15 of which replied. The results confirm the heterogeneity in surveillance systems, the weakness of many countries to adequately survey emerging water-related diseases, and the need for specific remedial action. The findings of the exercise will form the basis for future action under the Protocol on Water and Health.

An international parentage and identification panel for the domestic cat (Felis catus)

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations.

Simplified functional model for estimating nitrogen mineralisation and leaching in biosolids-amended soils

A model was developed to simulate biosolids mineralisation, nitrate leaching and nitrate uptake by plants. This functional model considers only the end product of a simplified treatment of the processes that occur without taking into account their rates. It is specifically structured for the use as a practical decision support tool for Sydney Water Corporation and other biosolids users for the beneficial application of biosolids on agricultural lands without nitrate accretion to groundwater. The model uses fundamental principles and the relevant concepts from available models to estimate movement of nitrate down the soil profile. The model output was compared against data from 3 independent experiments. In 1 experiment, biosolids were used in a sheep-grazing trial and in another, biosolids were applied to a winter wheat crop. In both cases, nitrate movement in soil was monitored by soil sampling. In a third experiment, bromide ion was used as a surrogate for nitrate to trace vertical solute movement under simulated rainfall. In all 3 experiments, the agreement of model predictions of nitrogen movement based on the distribution pattern and the position of the peak concentrations of nitrogen, with measured values was sufficient to support the validity of the model for nitrate movement in soil after biosolids application. The model is simple with easily available inputs and is of sufficient accuracy as a decision support tool in the management of biosolids application.

210Pb and 210Po determination in environmental samples

Sequential separation of 210Pb and 21OPo in environmental samples allows the determination of these naturally occurring radionuclides with good chemical yields and low detection limits. After sample mineralization, part of the leaching solution is used for 210Po determination which does not require any further treatment and essentially quantitative recoveries are obtained, using a standard 209Po tracer. The remaining part of the leaching solution is used for 210Pb determination. Starting from 3 g sediment (30 l water), the lower limits of detection of the method are 1.4 Bq kg(-1) (0.14 mBq l(-1)) for 210Pb and 0.25 Bq kg(-1) (0.016 mBq l(-1)) for 21OPo. The procedure has been checked by analysing two certified reference materials, supplied by IAEA, and reliable results have been obtained.

Structural stability of ribosomes subjected to RNase treatment evidenced by dielectric spectroscopy and differential scanning microcalorimetry

Previous studies from our laboratory demonstrated the existence of at least two levels of structural complexity in E. coli 70S ribosomes. Ribosomal RNA seems to be principally involved in the overall stability of these structures. In this paper we present an investigation of ribosomes subjected to treatment with RNase. The study is based on both differential scanning microcalorimetry and dielectric spectroscopy. In the thermograms obtained on treated ribosomes only the low temperature peak of the two typical denaturation events observed in native ribosomes, is promptly eliminated by the enzyme treatment. Dielectric spectroscopy measurements carried out on the same samples indicate an alteration of the dielectric behavior previously shown to consist of two subsequent relaxation processes. In fact, only the low frequency relaxation is affected by the treatment. The second one, observed at higher frequency, remains unaltered. The same effect on the dielectric parameters is observed if the ribosome particles are heated and then cooled prior to measurement. These results are consistent with the idea that two different structures are present within the ribosome. One is very stable and withstands both temperature and RNase treatment while the second is promptly abolished by both treatments. Data presented here strongly suggest that the RNA domains exposed to the solvent play a fundamental role in the stability of the 3-D structure of the ribosome particle.

Ingested soil as a source of 137Cs to ruminants

Ingestion of soil has been identified as a potentially important source of radionuclides, particularly to grazing ruminants. Soil artificially contaminated with radiocaesium was administered orally each day for 33 days to Bergamasca sheep and the transfer to milk measured. Two soil types were used, with a clay content of 11% and 16%, respectively. Transfer coefficient (fm) values to sheep milk, calculated at the equilibrium (period from 7th to 21st day after soil administration), were 3.72 x 10(-4) days l-1 (S.D. = 7.2 x 10(-5) days l-1) and 6.11 x 10(-4) days l-1 (S.D. = 9.1 x 10(-5) days l-1), respectively for the two soils. These low values indicate that radiocaesium is not removed from the binding sites on the clay minerals in the gut of the sheep.