D. De Lucia

Information retrieval models for recovering traceability links between code and documentation

The research described in the paper is concerned with the application of information retrieval to software maintenance, and in particular to the problem of recovering traceability links between the source code of a system and its free text documentation. We introduce a method based on the general idea of vector space information retrieval and apply it in two case studies to trace C++ source code onto manual pages and Java code onto functional requirements. The case studies discussed in the paper replicate the studies presented by G. Antoniol et al. (1999; 2000), respectively where a probabilistic information retrieval model was applied. We compare the results of vector space and probabilistic models and formulate hypotheses to explain the differences.

Erectile and endothelial dysfunction in Type II diabetes: a possible link.

Abstract.Aims/hypothesis: The aim of this study was to evaluate the relation between erectile dysfunction and endothelial functions, coagulation activation, peripheral and autonomic neuropathy in men with Type II (non-insulin-dependent) diabetes mellitus. Methods: We studied 30 Type II diabetic patients with symptomatic erectile dysfunction and 30 potent diabetic patients matched for age and disease. Endothelial functions were assessed with the l-arginine test, plasma thrombomodulin and cell adhesion molecules circulating concentrations. Haemostasis was evaluated with markers of thrombin activation and fibrinolysis. Quantitative sensory testing (vibratory, warming, and heat-pain thresholds), cardiovascular reflex tests and 24-h blood pressure monitoring were used to assess peripheral or autonomic neuropathy. Results: Mean erectile score and HbA1 c were 10.5 ± 5.8 and 8.3 ± 1.6 % in patients with erectile dysfunction, and 24.0 ± 0.7 and 6.8 ± 1.4 % in those without erectile dysfunction, respectively (p < 0.001); there was a significant relation between HbA1 c and erectile function score in patients with erectile dysfunction (r = –0.45, p = 0.02). The decrease in blood pressure and platelet aggregation in response to l-arginine was lower (p < 0.05–0.02) in patients with erectile dysfunction, whereas soluble thrombomodulin, P-selectin and intercellular cell ahhesion molecule-1 concentrations were higher (p < 0.05–0.02). Indices of coagulation activation (F1 + 2 and d-dimers) and reduced fibrinolysis (PAI-1) were also found to be higher in erectile dysfunction patients. Heat-pain and warm perception thresholds, as well as cardiovascular reflex tests, were most commonly abnormal in patients with erectile dysfunction (p < 0.05). In multivariate analysis, HbA1 c, MBP response to l-arginine, P-selectin, indices of coagulation, and quantitative sensory testing were independent predictors of erectile function score. Conclusion/interpretation: Erectile dysfunction in diabetic men correlates with endothelial dysfunction. A reduced nitric oxide activity might provide a unifying explanation. [Diabetologia (2001) 44: 1155–1160]

Software salvaging based on conditions

This paper presents algorithms for isolating reusable functions in large monolithic programs. The functions to be isolated are specified in terms of either pre-conditions or binding conditions, and these are mapped onto predicates on programs variables. Code components whose execution is triggered and/or bound by these predicates are then isolated. Each component is a candidate to implement a reusable function. The algorithms exploit a representation of the subject program in the form of a program dependence graph. This work forms part of RE/sup 2/, a research project that addresses the wider issue of software reuse. RE/sup 2/ project aims to promote the reuse of software through the exploration of reverse engineering and re-engineering techniques to identify and extract reusable software components from existing systems.<<ETX>>

Hypercoagulable state in patients with advanced gastrointestinal cancer: evidence for an acquired resistance to activated protein C.

Aims and background Thromboembolic complications are common in patients with cancer and represent the second cause of death in patients with overt malignant disease. The aim of this study was to investigate the activated protein C pathway in cancer. Methods We studied the coagulation cascade, natural clotting inhibitors, fibrinolytic proteins and resistance to activated protein C in 20 patients with advanced gastrointestinal cancer and 84 volunteers by measuring PT, APTT, fibrinogen, AT III, PC, PS, APC resistance, fibrinolytic system (PLG, ANPL, PAI-1 and t-PA) and activation peptides (D-Dimers, prothrombin 0 fragment 1+2/F1+2). Results Laboratory tests confirmed coagulation abnormalities in cancer patients. Fibrinogen, D-Dimers and F1+2 were increased, while t-PA activity was significantly lower than that of controls. APC resistance was higher in cancer patients compared to the control group (55% vs 2%; P < 0.0001). Excess thrombin generation was manifested by increased F1+2 plasma levels in APC-resistant cancer patients. Genetic analyses showed that only one patient with a poor response to APC carried a factor V R506Q mutation in exon 10. Conclusions Our findings show a high prevalence of APC resistance in cancer, compatible with an acquired defect in the APC pathway.

Subcortical ischaemic changes in young hypertensive patients: frequency, effect on cognitive performance and relationship with markers of endothelial and haemostatic activation

Information on subcortical ischaemic changes (SIC) in young hypertensive patients is scarce. We evaluated the frequency of SIC at magnetic resonance imaging (MRI), the possible effect on cognition of these patients, and the role of plasma markers known as indicators of endothelial and haemostatic activation. Inclusion criteria were age ≤54 years, hypertension for at least 2 years and absence of cerebrovascular disease or other conditions possibly related to SIC. Patients with SIC at MRI and two control groups (matched for age, sex and education) of hypertensive patients without SIC and non‐hypertensive healthy subjects underwent an extensive neuropsychological examination and evaluation of plasma markers. Amongst the 200 patients evaluated, 50 (25%) showed SIC at MRI. Mean age was 48.4 ± 4.8 years. Compared with both control groups, hypertensive patients with SIC performed significantly worse in general cognition, attention, memory and executive functions. Moreover, they showed significantly more often increased levels of all plasma markers compared with healthy controls, and of von Willebrand factor (vWF) compared with both control groups (P < 0.001). In young hypertensive patients SIC are frequent, related to a worse cognitive performance and endothelial dysfunction. Our findings suggest vWF as marker of end‐organ damage, underscoring the relevance of treating hypertension at younger age.

Short- and long-term treatments with iloprost in diabetic patients with peripheral vascular disease: effects on the cardiovascular risk factor plasminogen activator inhibitor type-1.

AbstractObjectives: Iloprost, an analogue of prostacyclin, is often utilised in subjects with diabetes mellitus complicated by macroangiopathy. Methods: The effects of iloprost infusion on plasminogen activator inhibitor type-1 (PAI-1), glucometabolic control and cardiovascular equilibrium in patients with type-2 diabetes mellitus and peripheral arterial occlusive disease were investigated. Thirteen (7 men/6 women) normal-weight, normotensive and non-smoker type-2 diabetic patients (63.8 ± 3.4 years, mean ± SD) with peripheral arterial occlusive disease, stage-II according to Fontaine classification, were enrolled. Eight (four men/four women) patients underwent three study designs, each separated by a 1-week interval: study I, infusion of iloprost (3 ng kg−1 min−1 for 5 h) for 1 day alone (short-term treatment); study II, infusion of saline (for 5 h) for 1 day (control treatment); study III, infusion of iloprost (3 ng kg−1 min−1 for 5 h) over a period of 28 days (long-term treatment). The remaining five (three men/two women) patients underwent study IV only, infusion of saline over a period of 28 days (placebo treatment). Plasma levels of glucose, plasminogen, PAI-1 activity and fibrinogen, blood pressure and heart rate were determined in all studies, while plasma insulin levels, blood HbA1c, walking distance and Winsor index only in studies III and IV. Results: Both short- and long-term treatments with iloprost significantly reduced PAI-1 activity (baseline vs end: 17.4 ± 1.9 AU/ml vs 15.0 ± 1.6 AU/ml, P < 0.02; 20.5 ± 7.6 AU/ml vs 7.9 ± 2.1 AU/ml, P < 0.002, respectively). Long-term treatment with iloprost significantly increased walking distance (baseline vs end: 325 ± 41 m vs 496 ± 52 m, P < 0.0001), but not Winsor index. Neither glucometabolic control nor cardiovascular equilibrium were affected by short- and long-term treatments with iloprost. Control and placebo treatments did not cause any significant modifications in the parameters evaluated. Conclusion: If confirmed by further investigations, the results of this pilot study suggest that iloprost, infused for both brief and long periods, is able to reduce the cardiovascular risk factor PAI-1, increases free walking capacity and does not affect glucometabolic control and blood pressure in type-2 diabetic patients complicated by macroangiopathy.

Specifying code analysis tools

Customised code analysis tools for the maintenance and evolution of existing software systems can be created by storing program information in a database, and using an application generator to translate the high-level specifications of the analyses the tools are intended to perform. We present a high-level domain-specific language for the specification of program analysis tools that exploit an algebraic program representation called F(p). The algebraic representation is a compact program view which describes the static composition of the control structures and the set of the resulting potential executions. Operands of the algebraic expression (that represent the programs constructs) are used as indexes to access information stored in the database. The specification language provides facilities for the traversal of the program representation and access to the associated information in the database. The program model and the analysis results are integrated into a unique conceptual model, thus simplifying the reuse of the results of an analysis and the integration of the tools.

Decrease in urokinase-type plasminogen activator (u-PA) levels in patients with non-insulin dependent diabetes mellitus

Summary The objective of the study was to investigate the activity and antigen levels of u-PA in non-insulin dependent diabetes mellitus (NIDDM) patients, and their changes after venous stasis. A cross-sectional case-control study was carried out in the out-patient diabetology clinical unit of the General Hospital in Pescara, Italy. Fifty-nine unselected NIDDM patients (23 females and 36 males; mean age 63±10, with diabetes definition by WHO criteria) were studied. A group of 50 subjects, age matched (age 58±9, 42 males, 8 females), without a history of diabetes, were consecutively recruited among healthy relatives of patients admitted to the hospital for surgical interventions to serve as a control group. The levels of both u-PA activity (scu-PA) and antigen (u-PA Ag) were significantly lower in NIDDM patients compared to controls. In contrast, t-PA, PAI-1 antigen and PAI activity levels were increased in NIDDM patients. There was no change in u-PA levels (both activity and antigen) after venous stasis, while t-PA levels were significantly increased. There was no difference in u-PA (both activity and antigen) and in t-PA levels between male and female patients. However, fibrinogen levels were lower and PAI-1, both antigen and activity, was higher in men than in women. No difference was found between patients with and without macrovascular complications in the parametres studied. Besides changes in t-PA and PAI-1 levels, NIDDM is also characterized by a decrease in u-PA activity and antigen levels. Such impairment of the fibrinolytic system, together with the increase in fibrinogen levels, could contribute to the prothrombotic condition peculiar to these patients.

Coagulation Derangements in Oral and Maxillofacial Surgery in Patients with a Documented Cancer: a Follow-up Study after Surgery

respectively, p < 0.001; Mann Whitney U-test). The plasma levels rapidly increased before surgery (348 + 55 mg/dL, 62 + 37 ng/mL, 116 + 33%, 2.9 + 1.4 nM and 355 + 105 ng/mL, respectively; p < 0.001; Fisher Exact Test), reaching the highest values after surgery (417 + 117 mg/dL, 75 + 41 ng/mL, 125 + 31%, 2.95 + 1.8 nM and 455 + 90.5 ng/mL, respectively; p < 0.001; Fisher Exact Test). Moderate titers of IgG anticardiolipin antibodies b2glycoprotein type I (> 10.5 IU/mL, cut-off point of 6.0 in our general population) were found in eight out of 15 patients. In agreement with other authors, analysis of our data suggests a state of hypercoagulability in cancer disease associated with maxillofacial surgery. The significant increase of plasma fibrinogen levels and the activation peptides (F1+2 and D-dimers) show a hypercoagulability state in this setting associated with endothelial cell activation and dysfunction (PAI-1 and F VIII), with thrombin formation and fibrin deposition (F1+2 and Ddimers). Therefore, analysis of our data also demonstrates a hypercoagulable state during the follow-up period of maxillofacial surgery associated with cancer disease (Lowry, 1995). Our report gave considerable information on the clinical situation when surgeons cause patients to become thrombophilic by removing their cancer. The mechanism that causes these coagulation derangements is still unknown; however, it is extremely complex and is partly related to coagulation alterations found in our patients. A better understanding of these mechanisms will help to prevent thrombo-embolic complications. The authors believe that it is mandatory to study coagulation cascade, fibrinolysis, and endothelial cell activation to prevent thrombotic events before OMF surgery.