The Utility of ctDNA in Lung Cancer Clinical Research and Practice: A Systematic Review and Meta-analysis of Clinical Studies

This systematic review with embedded meta-analysis aimed to evaluate the clinical utility of circulating tumor DNA (ctDNA) in lung cancer. After screening and review of the Embase database search, 111 studies from 2015 to 2020 demonstrated ctDNA's value in prognostication/monitoring disease progression, mainly in patients with advanced/metastatic disease and non-small cell lung cancer. ctDNA positivity/detection at any time point was associated with shorter progression-free survival and overall survival, whereas ctDNA clearance/decrease during treatment was associated with lower risk of progression and death. Validating these findings and addressing challenges regarding ctDNA testing integration into clinical practice will require further research.

Abstract 6695: Utility of circulating tumor DNA in breast cancer clinical research and practice: systematic review and meta-analysis

Background: Circulating tumor DNA (ctDNA) has been increasingly used in the clinical care of patients with cancer. This systematic review summarizes current data on the utility of ctDNA in breast cancer clinical research and practice and provides insights for integrating ctDNA into drug development and patient treatment.

Methods: The Embase database was used to identify original clinical research articles of ctDNA in breast cancer published from 2015 to 2020. ctDNA clinical utilities were reviewed and summarized, focusing on 3 areas: early diagnosis, prognostication, and monitoring disease progression/treatment response. Associations of ctDNA with disease-free survival (DFS) and overall survival (OS) were estimated in the embedded meta-analysis. Pooled estimates were calculated using fixed-effect or random-effect models depending on study heterogeneity.

Results: After screening and review, 72 articles were included. ctDNA studies have increased in recent years, with 59.7% of included articles published in 2019 or 2020. Overall, 61.1% of the studies were in patients with advanced stage/metastatic cancer; 45.8% were restricted to patients with specific cancer subtypes. ctDNA was minimally used in diagnosis; it was predominantly used in clinical outcome prediction with differences by stage. In patients with early-stage disease, the meta-analyses found that overall ctDNA detection/positivity was associated with shorter DFS (n=697; HR, 5.37; 95% CI, 2.94-9.80) and OS (n=238; HR, 4.60; 95% CI, 2.56-8.26). Specific gene mutations in ctDNA were mainly assessed in patients with advanced/metastatic disease, with mutations of ERBB, ESR1, and TP53 linked to shorter DFS in the meta-analyses (P<0.05). Moreover, current studies provided evidence that ctDNA reflects the dynamics of breast tumors in the patient treatment journey, acting as a biomarker to monitor tumor evolution and drug resistance.

Conclusions: Recent studies demonstrate ctDNA application in breast cancer prognostication/monitoring, suggesting an important role in patient stratification, molecular relapse identification, and personalized treatment. Large, multicenter clinical trials and real-world longitudinal data sets are needed to validate findings and to address challenges related to ctDNA to improve clinical utility and to integrate ctDNA testing into clinical practice and drug development.

Citation Format: Xuezheng Sun, Nicholas Ballew, Linda Kalilani, Kelesitse Phiri, Kelly Bell, Alexander Slowly, Magdalena Zajac, Erin Hofstatter, Angela Silvestro, Zebin Wang, Jeanne Schilder. Utility of circulating tumor DNA in breast cancer clinical research and practice: systematic review and meta-analysis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6695.

Impact of age at the time of the first ST-elevation myocardial infarction on 10-year outcomes. A sub-analysis from the EXAMINATION EXTEND trial

Background

The aim of this post-hoc sub analysis of the EXAMINATION-EXTEND study was to analyze 10-year outcomes according to the age of the patient at the time of the first STEMI.

Methods

Out of 1498 STEMI patients included in the EXAMINATION-EXTEND study, those with a previous history of atherosclerotic cardiovascular disease (coronary ischemic event, ischemic stroke, or previous coronary revascularization) were excluded for this analysis. The remaining 1375 patients were divided into three age groups: <55, 55–65 and >65 years. The primary endpoint was 10-year patient oriented composite endpoint (POCE) of all-cause death, any myocardial infarction (MI), or any revascularization. Secondary endpoints included the individual components of the primary endpoint, cardiac death, target vessel myocardial infarction (TVMI), target lesion revascularization (TLR), and stent thrombosis. The association between age and endpoints was adjusted for baseline confounders.

Results

At 10-year follow-up, patients <55 years (Adjusted hazard ratio [HR]: 0.42, 95% CI: 0.33–0.53, p=0.001), and 55–65 years (Adjusted HR: 0.44, 95% IC: 0.35–0.56, p=0.001) showed lower risk of POCE compared with those >65 years, led by a lower incidence of all-cause death (<55: 5.8% vs. 55–65: 11.3% vs. >65 years: 40.67%, p=0.001). Cardiac death was more prevalent in the older group (<55: 3.5% vs. 55–65: 5.5% vs. >65 years: 21.3%, p=0.001). There were not significant differences in the incidence of TVMI, TLR and stent thrombosis among the different age groups. In the landmark analyses, between 5 and 10-year follow-up, young patients exhibited higher incidence of any revascularization (<55: 7.4% vs. 55–65: 4.9% vs. >65 years: 1.7%, p=0.001) and a trend towards a higher incidence of any MI (<55: 5.2% vs. 55–65: 3.6% vs. >65 years: 1.5%, p=0.064). No differences were found in any other endpoints.

Conclusions

In patients with a first STEMI, advanced age was associated with high rates of POCE at 10-year follow-up, in particular, due to all-cause and cardiac death. Conversely, patients who presented at younger age exhibited a high risk of revascularization at long-term follow-up.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott Vascular

Generic Protocols for the Analytical Validation of Next-Generation Sequencing-Based ctDNA Assays: A Joint Consensus Recommendation of the BloodPAC's Analytical Variables Working Group

Liquid biopsy, particularly the analysis of circulating tumor DNA (ctDNA), has demonstrated considerable promise for numerous clinical intended uses. Successful validation and commercialization of novel ctDNA tests have the potential to improve the outcomes of patients with cancer. The goal of the Blood Profiling Atlas Consortium (BloodPAC) is to accelerate the development and validation of liquid biopsy assays that will be introduced into the clinic. To accomplish this goal, the BloodPAC conducts research in the following areas: Data Collection and Analysis within the BloodPAC Data Commons; Preanalytical Variables; Analytical Variables; Patient Context Variables; and Reimbursement. In this document, the BloodPAC's Analytical Variables Working Group (AV WG) attempts to define a set of generic analytical validation protocols tailored for ctDNA-based Next-Generation Sequencing (NGS) assays. Analytical validation of ctDNA assays poses several unique challenges that primarily arise from the fact that very few tumor-derived DNA molecules may be present in circulation relative to the amount of nontumor-derived cell-free DNA (cfDNA). These challenges include the exquisite level of sensitivity and specificity needed to detect ctDNA, the potential for false negatives in detecting these rare molecules, and the increased reliance on contrived samples to attain sufficient ctDNA for analytical validation. By addressing these unique challenges, the BloodPAC hopes to expedite sponsors' presubmission discussions with the Food and Drug Administration (FDA) with the protocols presented herein. By sharing best practices with the broader community, this work may also save the time and capacity of FDA reviewers through increased efficiency.

Collaborating to Compete: Blood Profiling Atlas in Cancer (BloodPAC) Consortium

The cancer community understands the value of blood profiling measurements in assessing and monitoring cancer. We describe an effort among academic, government, biotechnology, diagnostic, and pharmaceutical companies called the Blood Profiling Atlas in Cancer (BloodPAC) Project. BloodPAC will aggregate, make freely available, and harmonize for further analyses, raw datasets, relevant associated clinical data (e.g., clinical diagnosis, treatment history, and outcomes), and sample preparation and handling protocols to accelerate the development of blood profiling assays.

Abstract 272: Nanoscale high-throughput quantitative RT-PCR for the characterization of targeted-therapy related molecular biomarkers from recurrent and non-recurrent NSCLC tissues

Currently, there are no good biomarkers to predict targeted therapy outcomes for patients whose cancers recur vs. those that do not. Technology limitations have prevented extensive qRT-PCR biomarker analysis on small tumor tissue samples obtained in our unique lung cancer MD Anderson BATTLE clinical trials. Clinical sample size limitations are inherent due to the extremely small core needle biopsies (CNB) and fine needle aspirates (FNA). Identifying technology that can reliably analyze, in a quantitative manner, molecular biomarker signatures of 200-300 genes from CNB and FNA, will allow for comparative analysis of patients’ untreated tumor with treated follow-up tissue samples. We hypothesize RNA amplification coupled with nanoscale high-throughput (HT) qRT-PCR, will allow analysis of 320 gene expression patterns from 10ng RNA from frozen NSCLC tissues. We believe primary NSCLC tumors that recur have a different pattern of molecular abnormalities than NSCLCs from non-recurrent tumors (< 5 years), possibly accounting for lack of response to targeted therapy in some patients. RNA from 40 frozen adenocarcinoma (ADC) NSCLC tumor and matched normal cases with annotated clinicopathologic data was extracted/isolated and quantity/quality measured. 10ng from each sample was pre-amplified by WT-Ovation Pico protocol (NuGEN). Nanoscale high-throughput OpenArray quantitative RT-PCR (Life Technologies) with SYBR chemistry and DLD platform TaqMan chemistry was used to analyze 206 and 94 genes of interest, respectively, and 18 endogenous controls (EC). EC geometric mean was used for data normalization. Two-sample t-test was applied as test statistic for identifying differentially expressed genes in respect to recurrence, clinical stage, race and gender. Statistical significant level was set as p≤0.05. Statistical analysis was conducted using R packages. WT-Ovation Pico protocol successfully amplified all 10ng samples (mean = 235.2ng/ul, 1.94 260/280). OpenArray qRT-PCR successfully produced quantitative gene expression measurements as assessed by technical replicates (SD, median = 0.14; range = 0.00 to 12.70; R=0.931) and sample to sample correlation from chip to chip for each gene (Spearman Rho median = 0.3; range = −0.44 to 0.82). 14 genes included in the SYBR subset (KDRα, SLCO4A1α, ESR1α, TIE1α, EZH2α, VEGFAα, ADMα, CYP1A1α, NEO1α, CXCL5α, FGFR2α, HMBSα, ID1α, NRP2β) and 3 genes included in the TaqMan subset (DDX20α, CIDECα, PERPβ) were significantly dysregulated in recurrent vs. non-recurrent ADC NSCLCs. Amplification coupled with nanoscale HT qRT-PCR allowed for 320 quantitative gene expression measurements from 10ng RNA from NSCLC tissue. Data identified 17 genes with significantly dysregulated expression in recurrent vs. non-recurrent ADC NSCLCs. Supported in part by DoD PROSPECT grant W81XWH-07-1-0306.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 272. doi:1538-7445.AM2012-272

Vascular involvement in diabetic subjects with ischemic foot ulcer: a new morphologic categorization of disease severity

OBJECTIVES

Arteriographic lesions of diabetic subjects with critical limb ischemia (CLI) and ischemic foot ulcer were reviewed retrospectively, to provide new criteria for stratification of these patients on the basis of their vascular involvement.

PATIENTS

In 417 consecutive CLI diabetic subjects with ischemic foot ulcer undergoing lower limb angiography, lesions were defined as stenosis or occlusion, localization, and length (<5 cm, 5-10 cm, >10 cm). In a subgroup of 389 subjects, foot arteries also were evaluated. Patients then were categorized into 7 classes of progressive vascular involvement based on angiographic findings.

RESULTS

Of the 2893 found lesions (55% occlusions) 1% were in the iliac arteries, whereas 74% were in below-the-knee (BTK) arteries. Sixty-six % of all BTK lesions were occlusions, and 50% were occlusions >10 cm (p<0.001 vs proximal segments). Occlusions of all BTK were present in 28% of patients, although there was patency of at least one foot artery in 55% of patients. The morphologic Class 4 (two arteries occluded and multiple stenoses of tibial/peroneal and/or femoral/popliteal vessels) was the most common (36%). An inverse correlation between morphologic class and TcPO2 was observed (r=-0.187, p=0.003).

CONCLUSIONS

In CLI diabetic subjects with ischemic foot ulcer, the vascular involvement is extremely diffuse and particularly severe in tibial arteries, with high prevalence of long occlusions. A new morphologic categorization of these patients is proposed.

Incidence of hospital-acquired infections in Italian long-term-care facilities: a prospective six-month surveillance

This study presents results from a six-month prospective surveillance of hospital-acquired infections in four Italian long-term-care facilities (LTCFs). Eight hundred and fifty-nine patients were enrolled and 21 503 person-days were observed. Two hundred and fifty-four hospital-acquired infections (HAIs) occurred in 188 patients. The overall infection rate was 11.8 per 1000 person-days. The most frequent infections were urinary tract infections (3.2 per 1000 person-days), lower respiratory tract infections (2.7 per 1000 person-days) and skin infections (2.5 per 1000 person-days). Risks related to HAI in a multi-variate regression model were: length of stay >or=28 days [odds ratio (OR) 3.5, 95% confidence intervals (CI) 2.4-5.0]; presence of a device (OR 2.0, 95%CI 1.3-3.0); Norton scale <12 (OR 1.8, 95%CI 1.2-2.6); and being bedridden (OR 1.7, 95%CI 1.08-2.6). The presence of HAI increased the median length of stay (31 days vs 20 days, P<0.01) without a significant influence on fatal outcome (OR 1.4, 95%CI 0.7-2.7).

Association of Cardiovascular Risk Factors with Pattern of Lower Limb Atherosclerosis in 2659 Patients Undergoing Angioplasty

OBJECTIVES

Aim of this study is to correlate distribution pattern of lower limb atherosclerosis with cardiovascular risk factor profile of patients with peripheral arterial occlusive disease (PAD).

PATIENTS AND METHODS

Analysis is based on a consecutive series of 2659 patients (1583 men, 1076 women, 70+/-11 years) with chronic PAD of atherosclerotic origin undergoing primary endovascular treatment of lower extremity arteries. Pattern of atherosclerosis was grouped into iliac (n=1166), femoropopliteal (n=2151) and infrageniculate (n=888) disease defined according to target lesions treated. A multivariable multinomial logistic regression analysis was performed to assess relation with age, gender and classical cardiovascular risk factors (diabetes mellitus, arterial hypertension, hypercholesterolemia, cigarette smoking) using femoropopliteal disease as reference.

RESULTS

Iliac disease was associated with younger age (RRR 0.95 per year of age, 95%-CI 0.94-0.96, p<0.001), male gender (RRR 1.32, 95%-CI 1.09-1.59, p=0.004) and cigarette smoking (RRR 2.02, 95%-CI 1.68-2.42, p<0.001). Infrageniculate disease was associated with higher age (RRR 1.02, 95%-CI 1.01-1.02, p<0.001), male gender (RRR 1.23, 95%-CI 1.06-1.41, p=0.005) and diabetes mellitus (RRR 1.68, 95%-CI 1.47-1.92, p<0.001). Hypercholesterolemia was less prevalent in patients with lesions below the knee (RRR 0.82, 95%-CI 0.71-0.94, p=0.006), whereas no distinct pattern was apparent related to arterial hypertension.

CONCLUSION

Clinical phenotype of peripheral atherosclerosis varies with prevalence of cardiovascular risk factors suggesting differences in mechanisms involved in iliac as compared with infrageniculate lesions. Identification of molecular mechanism might have influence on future therapeutic strategies in PAD patients.

Automated software supported versus manual aorto-iliac diameter measurements in CT angiography of patients with abdominal aortic aneurysms: Assessment of inter- and intraobserver variation

Background: Open surgical or endovascular abdominal aortic aneurysm (AAA) relies on precise preprocedual imaging. Purpose of this study was to assess inter- and intraobserver variation of software-supported automated and manual multi row detector CT angiography (MDCTA) in aortoiliac diameter measurements before AAA repair. Patients and methods: Thirty original MDCTA data sets (4 times 2mm collimation) of patients scheduled for endovascular AAA repair were studied on a dedicated software capable of creating two-dimensional reformatted planes orthogonal to the aortoiliac center-line. Measurements were performed twice with a four-week interval between readings. Data were analysed by two blinded readers at random order. Two different measurement methods were performed: reader-assisted freehand wall-to-wall measurement and semi-automatic measurement. Results: Aortoiliac diameters were significantly underestimated by the semi-automatic method as compared to reader-assisted measurements (p < 0.0031). Intraobserver variability of AAA diameter calculation was not significant (p > 0.15) for reader-assisted measurements except for the diameter of the left common iliac artery in reader 2 (p = 0.0045) and it was not significant (p > 0.14) using the semi-automatic method. Interobserver variability was not significant for AAA diameter measurements using the reader-assisted method and for proximal neck analysis with the semi-automatic method (p > 0.27). Relevant interobserver variation was observed for semi-automatic measurement of maximum AAA (p = 0.0007) and iliac artery diameters (p = 0.024). Conclusions: Dedicated MDCTA software provides a useful tool to minimize aortoiliac diameter measurement variation and to improve imaging precision before AAA repair. For reliable AAA diameter analysis the reader-assisted freehand measurement method is recommended to be applied to a set of reformatted CT data as provided by the software used in this study.

Exercise increases soluble adhesion molecules ICAM-1 and VCAM-1 in patients with intermittent claudication

Adhesion molecules play a relevant role in the pathogenesis of vascular diseases. In 21 patients with intermittent claudication and 18 sex- and age-matched control subjects, we measured plasma levels of the circulating form of the adhesion molecules E-selectin, P-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) alongside von Willebrand factor (vWF), at rest, at maximally tolerated exercise and 5, 15 and 30 min after exercise. In controls, plasma sICAM-1 levels did not change with exercise, while in claudicants they increased from 285+/-15 to 317+/-16 ng/ml (p<0.01). Also for sVCAM-1 exercise did not modify plasma levels of sVCAM-1 in controls but increased it in claudicants from 671+/-45 to 751+/-47 ng/ml (p<0.05). Similarly, vWF did not change with exercise in controls, but increased in claudicants from 100+/-9% to 111+/-8% of value for pooled normal plasma (p<0.05). Exercise-induced changes in sICAM-1 negatively correlated with the maximal tolerated walking time, which is an index of disease severity. These findings indicate that, in claudicants, exercise is associated with increase in plasma levels of sICAM-1 and sVCAM-1.

Spinal-cord compression due to extradural amyloidosis of the cervico-occipital hinge, in a hemodialysed patient. A case report

Long-term dialysed patients can develop an arthropathy, called dialysis arthropathy, due to the deposition and transformation of the beta2 microglobulin into amyloid. The involvement of the spine, called destructive spondyloarthropathy (DSA), occurs between 10 and 25 percent; of these patients, and sometimes causes neurological damage. The disc space narrowing, vertebral body erosion and pseudocystis, in presence of polyarthropathy, chronic renal failure, and carpal tunnel syndrome, allows to make a diagnosis of DSA, which is proved by histological finding of beta2 microglobulin-amyloid. We report a rare case of spinal cord compression due to beta2 microglobulin-amyloid deposit in extradural space of cervico-occipital hinge.

Measurement of soluble adhesion molecules in primary Raynaud's phenomenon and in Raynaud's phenomenon secondary to connective tissue diseases

Adhesion molecules play a role in the inflammation and pathogenesis of vascular diseases. In 13 patients with primary Raynaud's phenomenon, 19 with Raynaud's phenomenon associated with connective tissue disease, and 16 control subjects, we measured plasma levels of soluble forms of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and von Willebrand factor. Patients with secondary Raynaud's phenomenon had plasma levels of soluble forms of intercellular adhesion molecule- 1, vascular cell adhesion molecule-1, E-selectin, and von Willebrand factor which were significantly higher than in those with primary Raynaud's phenomenon and controls, while no difference was observed between patients with primary Raynaud's phenomenon and controls. Within the group with secondary Raynaud's phenomenon, the strongest correlations were between soluble forms of intercellular adhesion molecule-1 and both E-selectin, (r=0.67, P<0.001) and von Willebrand factor (r=0.58, P<0.01). In none of the three groups were the levels of soluble adhesion molecules and von Willebrand factor changed by exposure of hands to cold, although all patients had a definite vasospasm. In conclusion, this study indicates that primary Raynaud's phenomenon is not associated with elevation of soluble adhesion molecules and von Willebrand factor. Prospective studies are now required to investigate the role of these molecules as predictors of secondary diseases.

High levels of adhesion molecules are associated with impaired endothelium-dependent vasodilation in patients with peripheral arterial disease

Soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cellular adhesion molecule-1 (sVCAM-1) were measured alongside flow-mediated vasodilation (FMD) in 34 patients with intermittent claudication and 14 control subjects. Patients with plasma sICAM-1 >253 ng/mL (median value) showed lower FMD than those with sICAM-1 < 253 ng/mL (5.6 +/- 1.8% vs 9.6 +/- 4.2%, p < 0.01). Similarly, in the 17 patients with plasma sVCAM-1 > 414 ng/mL, FMD was lower than in the remaining 17 patients (6.1 +/- 1.9% vs 9.2 +/- 4.5%, p < 0.05). Additionally, when endothelial dysfunction was defined as FMD < or = 5.5%, patients with FMD below this value had higher plasma concentrations of sICAM-1 and sVCAM-1 than those with FMD > 5.5%. Therefore, our findings indicate a close association between elevated plasma levels of adhesion molecules and endothelial dysfunction. As impaired endothelial function is one of the first steps in atherogenesis, our findings have clinical relevance since they serve as the basis for further evaluation of sICAM-1 and sVCAM-1 as potential plasma markers for progression of atherosclerosis in a population at high risk.

[A new questionnaire for assessing the quality of life of patients with intermittent claudication]

BACKGROUND

Quality of life assessment is becoming increasingly relevant for evaluating the impact of disease and treatments and for deciding priorities when allocating resources. This is especially true in intermittent claudication where the goal of therapy is not the cure of the disease but rather to alleviate its symptoms and improve the patient's functional capabilities. At present, however, no generic scale fits all criteria for the ideal quality of life measuring in intermittent claudication.

METHODS

We developed a questionnaire aimed at evaluating the specific limitations encountered by claudicants in the physical activity and in the social and emotional functioning. The present study evaluated the questionnaire for validity, reliability, and sensitivity to change, attributes considered to be essential for a questionnaire to be useful.

RESULTS

In 30 patients with intermittent claudication, the scores of the four sections of the questionnaire significantly correlated with the scores of the corresponding sections of the Nottingham Health Profile. This indicates that the questionnaire is valid. For each of the four subscales, the intraclass correlation coefficient was > 0.75, thus showing a high test re-test reliability. Also the internal consistency is strong with alpha coefficient ranging from 0.79 to 0.89. Finally, the questionnaire was administered to 9 patients before and 4 weeks after percutaneous transluminal angioplasty for claudication. After the intervention, the improvement in walking performance paralleled the improvement in quality of life. This indicates that the questionnaire is sensitive to change.

CONCLUSIONS

Our questionnaire appears to be a valid and reliable quality of life measure in intermittent claudication.

[Nurses' perception of specific nursing activities that can be delegated to other health care personnel]

In order to understand the nurses' perception of the activities specific to nursing care, and to assess what they are ready to delegate to other health care workers, a complex activity of analysis was started. Head nurses and nurses representative of the different NHS hospital and district services (hospital wards, home care and district, preventive services, psychiatric services and first aid services in the district, operating theatre and clinics) of the Medio Friuli area (North of Italy) were asked to identify a. the main activities performed in the patients' care, b. the nature of the activities (whether administrative, hotel, health, support-non health), c. their level of standardization (i.e. whether their performance required discretionality and the tailoring of the activity to the patient's situation) and d. if they considered it delegable and to whom (doctors, support personnel, secretary, other health care personnel). Final aim of the work was to acquire elements in order to reorganize the nursing care. In order to leave the nurses free to identify areas that better allowed the description of their activities, (and due to the large and different numbers of sectors and areas involved), no strict instructions were given. Therefore the model used and level of detail in the description of activities and processes varied from group to group. Sixty nurses participated in the work. On average, from 38.9% (Operating Theatre and clinics) to 55.7% (Psychiatric services) of the activities identified were perceived as delegable to nurses aids and/or secretaries. The 89.2% of delegable activities (183/205) were considered highly standardized. Up to 23.4% (39/166) were classified as health care activities (i.e. prevention of pressure sores with mobilization, risk assessment with standardized scales, application of ointments, the care for patients during mobilization etc.). The remaining were classified as administrative or support activities. Although this does not necessarily imply that with the introduction in the health care team of a secretary and of the nurse-aid half of the time of the nurse could be freed, nurses perceive that on average half of their routine and basic activities could be well delegated to other figures.

Microcirculation and tissue metabolism in peripheral arterial disease

It is now clear that different pathophysiologic mechanisms have a profound influence on the extent of the functional impairment in intermittent claudication. In particular, metabolic derangements, including impaired oxygen delivery and/or extraction, reduced nitric oxide synthesis, reduced glucose oxidation, accumulation of toxic metabolites and reduction in carnitine availability are correlated with disease severity. Therefore, metabolic interventions aimed at counteracting these alterations may represent a valid therapeutic approach to the treatment of this condition. To date, verapamil and L-arginine efficacy has been proven in few patients; a large scale clinical trial, conversely, reports that propionyl-L-carnitine appears to be an effective and well tolerated drug for the treatment of intermittent claudication.

The inducible trimethylamine N-oxide reductase of Escherichia coli K12: its localization and inducers

We used an anti-trimethylamine-N-oxide reductase (EC 1.6.6.9) serum and different immunological techniques (Ouchterlony, rocket immunoelectrophoresis, immunoblotting) to show that dimethylsulphoxide (DMSO), tetrahydrothiophene 1-oxide (THTO) and pyridine N-oxide (PNO) were effective inducers of the inducible form of trimethylamine N-oxide reductase. We confirmed this genetically and biochemically using a strain in which phage MudII 1734 carrying lacZ was inserted into torA, the structural gene for inducible trimethylamine-N-oxide reductase. By subcellular fractionation and quantitation with rocket immunoelectrophoresis, we showed that the enzyme was principally localized in the periplasmic fraction. Constitutive trimethylamine-N-oxide reductase was localized in the membrane fraction and, like the inducible enzyme showed a broad specificity with respect to various compounds such as DMSO, THTO and PNO. Apart from their immunological properties, the two enzymes could be clearly differentiated by their temperature stability.

An integrated approach to the assessment of family adjustment to acute lymphocytic leukemia in children

This study evaluated psychological distress, social support and adjustment to the disease of 69 parents of 35 children suffering from acute lymphocytic leukemia. The study dealt with the initial phase of the disease. The following rating scales were used: the Symptom Distress Checklist-90, the Social Support Questionnaire and the Family Adjustment Scale. Psychological distress of the mothers was negatively correlated with their and their child's adjustment to the disease. A similar trend was found for fathers but the correlations reached statistical significance only for fathers' adjustment. Social support as evaluated by the 2 parents was positively correlated with their and their child's adjustment to the disease experience.

The inducible trimethylamine-N-oxide reductase of Escherichia coli K12: biochemical and immunological studies

The inducible trimethylamine-N-oxide reductase which migrates on non-denaturing polyacrylamide gels with an RF of 0.22, has been purified from the soluble fraction of wild-type E. coli K12. The molecular weight of the purified enzyme estimated by molecular-sieve chromatography is about 230,000. It is composed of two subunits of molecular weight 110,000. Antiserum specific for the enzyme has been produced. Gel filtration on Sephadex G-200 of the soluble fraction gave two peaks of trimethylamine-N-oxide reductase, one with an Mr of 230,000 and an RF of 0.22, and another with an Mr of 120,000 and an RF of 0.36. Since the anti-trimethylamine-N-oxide reductase serum recognises the two forms and shows a single subunit with an Mr of 110,000, we conclude that in E. coli there is a single inducible trimethylamine-N-oxide reductase which can exist as a dimer or a monomer. Other immunological studies with anti-trimethylamine-N-oxide reductase serum on crude extracts prepared from cells grown in the absence of inducer showed that the constitutive trimethylamine-N-oxide reductase was not recognised by the antiserum. The same analyses carried out on a tor mutant (defective in the structural gene of the inducible enzyme) confirmed without ambiguity that the constitutive enzyme is immunologically distinct from the inducible enzyme. In the same way, using the anti-trimethylamine-N-oxide reductase serum, rocket immunoelectrophoresis analyses were able to show that the inducible apoenzyme is not regulated by the fnr gene product and that molybdate does not seem necessary for the synthesis or stabilisation of this enzyme.

Clomipramine-induced pancytopenia

A 54-year old man developed pancytopenia after receiving clomipramine for a major depressive episode with psychotic features. The discontinuation of the drug determined a significant improvement of the hematological picture.

Social support and psychological distress of parents of children with acute lymphocytic leukaemia

The relationship between psychological distress and social support was evaluated in 26 parents of children with acute lymphocytic leukaemia during the diagnostic phase. The Symptom Distress Checklist and the Social Support Questionnaire were used. A high percentage of subjects reported a score of moderate psychological distress in four subscales of the Symptom Checklist: Obsessiveness-Compulsiveness (46 per cent), Depression (61.5 per cent), Anxiety (65 per cent) and Sleep Disturbances (57.5 per cent). Social support for parents was found to have a "buffering' effect on the impact of the stress occasioned by the diagnosis of acute lymphocytic leukaemia in a child.

Molybdenum cofactor: a compound in the in vitro activation of both nitrate reductase and trimethylamine-N-oxide reductase activities in Escherichia coli K12

Nitrate reductase (nitrite: (acceptor) oxidoreductase, EC 1.7.99.4) and trimethylamine N-oxide reductase (NADH : trimethylamine-N-oxide oxidoreductase, EC 1.6.6.9) activities were reconstituted by incubation of the association factor FA (the putative product of the chlB gene) with the soluble extract of the chlB mutant grown anaerobically in the presence of trimethylamine N-oxide. When soluble extracts of the chlB mutant grown on 10 mM sodium tungstate, a molybdenum competitor, were used in complementation systems, no enzymatic reactivation was observed. Heated extracts of the parental strain 541 were shown to contain a thermoresistant molybdenum cofactor by their ability to reactivate NADPH-nitrate reductase activity in the nit1 mutant of Neurospora crassa. By complementation of parental strain heated extract with association factor FA and soluble extract of the chlB mutant grown in the presence of sodium tungstate, we were able to show for the first time that the molybdenum cofactor is an activator common to the in vitro reconstitution of both nitrate reductase and trimethylamine-N-oxide reductase activities.