Exploring the Effects of LED-Based Visible Light Communication on Reading and Color Perception in Indoor Environments: An Experimental Study

Visible light communications (VLC) is a technology that enables the transmission of digital information with a light source. VLC is nowadays seen as a promising technology for indoor applications, helping WiFi to handle the spectrum crunch. Possible indoor applications range from Internet connection at home/office to multimedia content delivery in a museum. Despite the vast interest of researchers in both theoretical analysis and experimentation on VLC technology, no studies have been carried out on the human perceptions of objects illuminated by VLC-based lamps. It is important to define if a VLC lamp decreases the reading capability or modifies the color perception in order to make VLC a technology appropriate for everyday life use. This paper describes the results of psychophysical tests on humans to define if VLC lamps modify the perception of colors or the reading speed. The results of the reading speed test showed a 0.97 correlation coefficient between tests with and without VLC modulated light, leading us to conclude that there is no difference in the reading speed capability with and without VLC-modulated light. The results of the color perception test showed a Fisher exact test p-value of 0.2351, showing that the perception of color is not influenced by the presence of the VLC modulated light.

Signal Processing Techniques for 6G

6G networks have the burden to provide not only higher performance compared to 5G, but also to enable new service domains as well as to open the door over a new paradigm of mobile communication. This paper presents an overview on the role and key challenges of signal processing (SP) in future 6G systems and networks from the conditioning of the signal at transmission to MIMO precoding and detection, from channel coding to channel estimation, from multicarrier and non-orthogonal multiple access (NOMA) to optical wireless communications and physical layer security (PLS). We describe also the core future research challenges on technologies including machine learning based 6G design, integrated communications and sensing (ISAC), and the internet of bio-nano-things.

EEG Authentication System Based on One- and Multi-Class Machine Learning Classifiers

In the current Information Age, it is usual to access our personal and professional information, such as bank account data or private documents, in a telematic manner. To ensure the privacy of this information, user authentication systems should be accurately developed. In this work, we focus on biometric authentication, as it depends on the user's inherent characteristics and, therefore, offers personalized authentication systems. Specifically, we propose an electrocardiogram (EEG)-based user authentication system by employing One-Class and Multi-Class Machine Learning classifiers. In this sense, the main novelty of this article is the introduction of Isolation Forest and Local Outlier Factor classifiers as new tools for user authentication and the investigation of their suitability with EEG data. Additionally, we identify the EEG channels and brainwaves with greater contribution to the authentication and compare them with the traditional dimensionality reduction techniques, Principal Component Analysis, and χ2 statistical test. In our final proposal, we elaborate on a hybrid system resistant to random forgery attacks using an Isolation Forest and a Random Forest classifiers, obtaining a final accuracy of 82.3%, a precision of 91.1% and a recall of 75.3%.

The Role of Bidirectional VLC Systems in Low-Latency 6G Vehicular Networks and Comparison with IEEE802.11p and LTE/5G C-V2X

In this paper, we present very recent results regarding the latency characterization of a novel bidirectional visible light communication (VLC) system for vehicular applications, which could be relevant in intelligent transportation system (ITS) safety applications, such as the assisted and automated braking of cars and motorbikes in critical situations. The VLC system has been implemented using real motorbike head- and tail-lights with distances up to 27 m in a realistic outdoor scenario. We performed a detailed statistical analysis of the observed error distribution in the communication process, assessing the most probable statistical values of expected latency depending on the observed packet error rate (PER). A minimum attainable observed round-trip latency of 2.5 ms was measured. Using our dataset, we have also estimated the probability to receive correctly a message with a specific average latency for a target PER, and we compare it to the ultra-reliable low-latency (URLL) 5G communications service. In addition, a mobility model is implemented to compare the VLC and radio frequency (RF) technologies (IEEE802.11p, LTE, 5G) to support an automated braking systems for vehicles in urban platooning.

Ultra-Wideband Radar-Based Indoor Activity Monitoring for Elderly Care

In this paper, we propose an unobtrusive method and architecture for monitoring a person’s presence and collecting his/her health-related parameters simultaneously in a home environment. The system is based on using a single ultra-wideband (UWB) impulse-radar as a sensing device. Using UWB radars, we aim to recognize a person and some preselected movements without camera-type monitoring. Via the experimental work, we have also demonstrated that, by using a UWB signal, it is possible to detect small chest movements remotely to recognize coughing, for example. In addition, based on statistical data analysis, a person’s posture in a room can be recognized in a steady situation. In addition, we implemented a machine learning technique (k-nearest neighbour) to automatically classify a static posture using UWB radar data. Skewness, kurtosis and received power are used in posture classification during the postprocessing. The classification accuracy achieved is more than 99%. In this paper, we also present reliability and fault tolerance analyses for three kinds of UWB radar network architectures to point out the weakest item in the installation. This information is highly important in the system’s implementation.

Efficient Hybrid Particle-Field Coarse-Grained Model of Polymer Filler Interactions: Multiscale Hierarchical Structure of Carbon Black Particles in Contact with Polyethylene

In the present study, we propose, validate, and give first applications for large-scale systems of coarse-grained models suitable for filler/polymer interfaces based on carbon black (CB) and polyethylene (PE). The computational efficiency of the proposed approach, based on hybrid particle-field models (hPF), allows large-scale simulations of CB primary particles of realistic size (∼20 nm) embedded in PE melts. The molecular detailed models, here introduced, allow a microscopic description of the bound layer, through the analysis of the conformational behavior of PE chains adsorbed on different surface sites of CB primary particles, where the conformational behavior of adsorbed chains is different from models based on flat infinite surfaces. On the basis of the features of the systems, an optimized version of OCCAM code for large-scale (up to more than 8 million of beads) parallel runs is proposed and benchmarked. The computational efficiency of the proposed approach opens the possibility of a computational screening of the bound layer, involving the optimal combination of surface chemistry, size, and shape of CB aggregates and the molecular weight distribution of the polymers achieving an important tool to address the polymer/fillers interface and interphase engineering in the polymer industry.

Diabetic foot infections: a comprehensive overview

Diabetic foot ulcers (DFUs), a micro-vascular complication, are associated with a substantial increase in morbidity and mortality. DFUs are a complicated mixture of neuropathy, peripheral arterial diseases, foot deformities, and infections. Foot infections are frequent and potentially devastating complications. Infection prospers in more than half of all foot ulcers and is the factor that most often leads to lower extremity amputation. The complications of microbial flora span the spectrum from superficial cellulitis to chronic osteomyelitis and gangrenous extremity lower limb amputations. Wounds without confirmed soft tissue or bone infections do not require antibiotic therapy. Mild and moderate infections need empiric therapy covering Gram-positive cocci, while severe infections caused by drug-resistant organisms require broad-spectrum anti-microbials targeting aggressive Gram-negative aerobes and obligate anaerobes.

A Flexible Wireless Sensor Network Based on Ultra-Wide Band Technology for Ground Instability Monitoring

An innovative wireless sensor network (WSN) based on Ultra-Wide Band (UWB) technology for 3D accurate superficial monitoring of ground deformations, as landslides and subsidence, is proposed. The system has been designed and developed as part of an European Life+ project, called Wi-GIM (Wireless Sensor Network for Ground Instability Monitoring). The details of the architecture, the localization via wireless technology and data processing protocols are described. The flexibility and accuracy achieved by the UWB two-way ranging technique is analysed and compared with the traditional systems, such as robotic total stations (RTSs) and Ground-based Interferometric Synthetic Aperture Radar (GB-InSAR), highlighting the pros and cons of the UWB solution to detect the surface movements. An extensive field trial campaign allows the validation of the system and the analysis of its sensitivity to different factors (e.g., sensor nodes inter-visibility, effects of the temperature, etc.). The Wi-GIM system represents a promising solution for landslide monitoring and it can be adopted in combination with traditional systems or as an alternative in areas where the available resources are inadequate. The versatility, easy/fast deployment and cost-effectiveness, together with good accuracy, make the Wi-GIM system a possible solution for municipalities that cannot afford expensive/complex systems to monitor potential landslides in their territory.

Metabolic control and complications in Italian people with diabetes treated with continuous subcutaneous insulin infusion

BACKGROUND AND AIM

The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII).

METHODS AND RESULTS

Questionnaires investigating the organisation of diabetes care centres, individuals' clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA_1c) level was 60 mmol/mol (7.6%). The HbA_1c target (i.e. <58 mmol/mol for age <18 years and <53 mmol/mol for age >18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA_1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis.

CONCLUSIONS

Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 02620917 (ClinicalTrials.gov).

Basal insulin initiation in primary vs. specialist care: similar glycaemic control in two different patient populations

OBJECTIVE

To investigate the effect of healthcare provider (HCP) type (primary vs. specialist) on glycaemic control and other treatment parameters.

RESEARCH DESIGN AND METHODS

Study of Once-Daily Levemir (SOLVE(™) ) is an international, 24-week, observational study of insulin initiation in people with type 2 diabetes.

RESULTS

A total of 17,374 subjects were included, comprising 4144 (23.9%) primary care subjects. Glycaemic control improved in both HCP groups from baseline to final visit [glycated haemoglobin (HbA1c) -1.2 ± 1.4% (-13.1 ± 15.3 mmol/mol) and -1.3 ± 1.6% (-14.2 ± 17.5 mmol/mol), respectively]. After adjustment for known confounders, there was no statistically significant effect of HCP group on final HbA1c [-0.04%, 95% confidence interval (CI) -0.09 to -0.01 (-0.4 mmol/mol, 95% CI -1.0-0.1 mmol/mol), p = 0.1590]. However, insulin doses at the final visit were higher in primary care patients (+0.06, 95% CI 0.06-0.07 U/kg, p < 0.0001). Logistic regression demonstrated a significant effect of HCP type (primary vs. specialist care) on hypoglycaemia risk [odds ratio (OR) 0.75, 95% CI 0.64-0.87, p = 0.0002]. Primary care physicians took more time to train patients and had more frequent contact with patients than specialists (both p < 0.0001).

CONCLUSIONS

Primary care physicians and specialists achieved comparable improvements in glycaemic control following insulin initiation.

Safety and effectiveness of insulin detemir in combination with oral antidiabetic agents in an outpatient specialist setting: results of the Italian SOLVE™ observational study

AIM

The addition of basal insulin to oral antidiabetics (OADs) is described by a large number of guidelines and commonly used in clinical practice as a way to start insulin therapy in patients with type 2 diabetes mellitus in order to maximize compliance and minimise the impact of side effects (mainly hypoglycemia and body weight increase).

METHODS

SOLVE™ was a 24-week international observational study conducted in 10 countries (including Italy) for the evaluation of the safety and effectiveness of once-daily insulin detemir as add-on therapy in patients with type 2 diabetes mellitus (T2DM) already treated with one or more OADs. The Italian arm of the Solve™ Study aimed to evaluate the safety and the effectiveness of once-daily insulin detemir in combination with OAD agents for the treatment of patients with T2DM in the Italian outpatient specialist setting. The primary endpoint was to assess the incidence of serious adverse drug reactions (SADRs) including in the specific major hypoglycemic events during 24 weeks of once-daily insulin detemir treatment.

RESULTS

A total of 4625 patients were enrolled in the study by 223 Italian centres for diabetes care. At baseline the mean (±SD) demographic characteristics of the patients were: age 66.5 (±10.0) years, duration of diabetes 13.25 (±8.14) years, weight 78.95 (±15.86) kg and BMI 29.5 (±5.0) kg/m2. At the end of the study, 3 SADRs (of which 2 were major hypoglycemia) were reported in 2 patients (<0.1%). The percentage of patients with at least 1 minor hypoglycemic event during the 4 weeks preceding insulin initiation was 3.6%. Following insulin initiation, 5.7% (as recorded at baseline visit) had at least 1 minor hypoglycemic event, which decreased slightly by the end of the study compared to baseline (4.8%). In addition, before insulin initiation the mean (±SD) glycemic control values were: fasting plasma glucose (FPG) 11.43 (±3.2) mmol/L and HbA1c 9.16% (±1.46). At the end of the study, HbA1c was reduced by 1.35% (±1.57) (P<0.001), FPG was reduced by 3.34 mmol/L (P<0.001) and the percentage of patients with HbA1c<7% was 21.9%. A mean reduction of 0.52 kg of body weight (P<0.001) was observed compared to before insulin initiation; the body weight reduction was more pronounced in patients with higher BMI before insulin initiation (-1.0 kg for 30<BMI<35; -2.1 kg for BMI<35).

CONCLUSION

In the Italian outpatient setting, once-daily insulin detemir as add-on therapy to OADs was associated with a favourable tolerability profile. The improvement of the glycemic control after initiation with insulin detemir was clinically significant and did not cause an increase in body weight or hypoglycemia.

Atherosclerotic coronary plaque in subjects with diabetic neuropathy: the prognostic cardiovascular role of Charcot neuroarthropathy--a case-control study

The aim of this study was to investigate the severity of coronary artery disease (CAD) and the plaque composition in neuropathic type 2 diabetic subjects with and without Charcot neuroarthropathy (CN) undergoing multidetector computed tomography coronary angiography (MDCT-CA). The study was a single-center, observational, with unmatched case-control design. We selected 17 CN patients and 18 patients with diabetic neuropathy (DN) without CN. In all the patients, multidetector computed tomography was performed to assess the coronary artery calcium score (CACS) and degree of coronary artery stenosis. Patients were classified as positive in the presence of significant CAD if there was at least one stenosis >50 % on MDCT-CA. The invasive coronary angiography was performed in case of significant stenosis detected with MDCT-CA, both as reference to standard and eventually as treatment. Groups were matched for age, sex, and traditional CAD risk factors. As compared to DN individuals, CN exhibited higher rates of significant coronary stenoses (p = 0.027; OR 7.7 [1.3-43.5]). However, no significant differences were observed in the CACS, which reflects plaque burden, in the two groups (p = 0.759). No significant differences were observed comparing CACS distribution in all subjects for stenosis higher/equal or lower than 50 % (p = 0.320). Finally, no significant differences were observed comparing CACS distribution in CN and DN subjects for coronary stenoses higher/equal or lower than 50 %. Our results suggest that CN patients have a higher prevalence of severe coronary plaques compared to DN patients. Nevertheless, coronary plaques in CN patients did not exhibit an increased degree of calcification.

Effect of once-daily insulin detemir on oral antidiabetic drug (OAD) use in patients with type 2 diabetes

WHAT IS KNOWN AND OBJECTIVE

There are acknowledged benefits to continuing metformin when initiating insulin, but there appears to be growing concern over the role of sulphonylureas and thiazolidinediones when used in combination with insulin. This analysis investigates the effects of continuing or discontinuing oral antidiabetic drugs (OADs) following the initiation of once-daily insulin detemir.

METHODS

SOLVE is a 24-week, multinational observational study of insulin detemir initiation in patients with type 2 diabetes mellitus treated with one or more OADs.

RESULTS

In the total cohort (n = 17 374), there were significant improvements in HbA1c (-1·3%, 95% CI -1·34; -1·27%) and weight (-0·6 kg, 95% CI -0·65; -0·47 kg), with an increase in the incidence rate of minor hypoglycaemia (+0·256 events ppy, P < 0·001), but not severe hypoglycaemia (-0·038 events ppy, P < 0·001). Study participants had information on OAD use either prior to (n = 17 086) or during insulin initiation (n = 16 346). HbA1c reductions were significantly greater in patients continuing treatment with metformin (-1·3% vs. -1·1%, P < 0·01), thiazolidinediones (-1·3% vs. -1·0%, P < 0·01) and DPP-IV inhibitors (-1·3% vs. -0·9%, P < 0·001). Final insulin doses were significantly greater in patients discontinuing treatment with sulphonylureas (0·29 vs. 0·26 IU/kg, P < 0·001), glinides (0·28 vs. 0·26 IU/kg, P < 0·01), thiazolidinediones (0·31 vs. 0·26 IU/kg, P < 0·001) and DPP-IV inhibitors (0·35 vs. 0·29 IU/kg, P < 0·001) compared with patients continuing these respective agents. All patient subgroups had a mean weight loss irrespective of OAD continuation, apart from those continuing thiazolidinediones (+0·2 kg). The largest improvements in weight were seen following the withdrawal of sulphonylureas and thiazolidinediones (-1·1 and -1·1 kg, respectively).

WHAT IS NEW AND CONCLUSION

Discontinuation (or switching) of OADs at the time of insulin initiation appears to be governed principally by concerns about hypoglycaemia and weight. HbA1c improvements were smaller in patients discontinuing OADs at the time of insulin initiation and may be associated with insufficient insulin titration.

Safety and efficacy of insulin aspart and soluble human insulin in Type 2 diabetes mellitus

AIM

The UpGrade study evaluated the safety profile and effectiveness of insulin aspart (IAsp, NovoRapid®) and soluble human insulin (SHI) in patients with Type 2 diabetes mellitus, under current clinical practice conditions.

METHODS

This 26-week, open-label, non-randomized, observational safety study recruited patients using insulin ± metformin and having received ≥ 2 injections of IAsp or SHI over a period of 3 months to 3 years. Data were collected via patient recall and treatment diaries, at baseline, 13- and 26-week visits. The number of major hypoglycemic episodes was the primary endpoint. Secondary endpoints were minor hypoglycemic episodes, HbA1c, fasting and post-prandial blood glucose.

RESULTS

Overall, 4099 patients were included. At study end the incidence of major hypoglycemia was low (mean rate 0.117 ev/pt-y) and rates were lower in subjects using IAsp compared with those using SHI, for both major (0.115 vs. 0.121) and minor (6.648 vs. 9.530) episodes. IAsp correlated with a significantly lower risk of minor hypoglycemic episodes (IRR=0.64, P<0.0001). Overall, HbA1c levels decreased across 26 weeks (7.97% to 7.63%, P<0.0001); IAsp had greater HbA1c reduction than SHI (-0.39% and -0.22%, respectively) and was associated with a marginally significant likelihood (vs. SHI) of achieving HbA1c reduction of ≥ 0.5% (OR=1.22, P=0.059).

CONCLUSION

Under current clinical practice conditions, treatment of patients with Type 2 diabetes mellitus using either IAsp or SHI resulted in low rates of major hypoglycemia after 26 weeks. Patients using IAsp had a better clinical safety profile and a greater reduction in HbA1c compared with patients using SHI.

The safety and efficacy of adding once-daily insulin detemir to oral hypoglycaemic agents in patients with type 2 diabetes in a clinical practice setting in 10 countries

AIMS

Evaluate the safety and efficacy of once-daily insulin detemir initiated in routine clinical practice in patients with type 2 diabetes mellitus inadequately controlled with oral hypoglycaemic agents (OHAs).

METHODS

This large observational study was conducted in 10 countries. Adverse event data (including hypoglycaemia) and glycaemic control were recorded before and 24 weeks following insulin initiation while patients continued routine clinical management.

RESULTS

In this study, 17 374 patients (53% male) were included. Mean pre-insulin values (±s.d.) were: age 62 ± 12 years; body mass index (BMI) 29.3 ± 5.4 kg/m(2); diabetes duration 10 ± 7 years; haemoglobin A1c (HbA1c) 8.9 ± 1.6%. During the study, 27 patients experienced serious adverse drug reaction, severe hypoglycaemic events or both; and there were 31 episodes of severe hypoglycaemia in 21 patients. After 24 weeks, HbA1c was 7.5 ± 1.2% (change of -1.3%; p < 0.001) and mean weight change was -0.6 kg (confidence interval -0.7, -0.5 kg, p < 0.001). Daily insulin dose increased from 13 ± 6 U (0.16 ± 0.09 U/kg) to 22 ± 16 U (0.27 ± 0.17U/kg) by 24 weeks. Multivariate regression analysis identified several independent demographic and treatment predictors of end of study HbA1c.

CONCLUSIONS

Addition of once-daily insulin detemir to patients with type 2 diabetes mellitus on OHA therapy resulted in few adverse events, significant improvements in glycaemic control, small reductions in weight and low rates of hypoglycaemia. On the basis of this study, concerns about hypoglycaemia or weight gain should not preclude initiation of basal insulin analogues in patients with poor glycaemic control on OHAs.

Weight beneficial treatments for type 2 diabetes

CONTEXT

The close link between type 2 diabetes and excess body weight highlights the need to consider the weight effects of different treatment regimens. We examine the impact of "weight-friendly" type 2 diabetes pharmacotherapies and suggest treatment strategies that mitigate weight gain.

EVIDENCE ACQUISITION

Evidence was identified via PubMed search by class and agent and in bibliographies of review articles, with final articles for inclusion selected by author consensus.

EVIDENCE SYNTHESIS

Substantial evidence confirms the weight benefits of metformin and shows that, of the newer available agents, glucagon-like peptide-1 (GLP-1) agonists and amylin analogs promote weight loss. Dipeptidyl peptidase-4 (DPP-4) inhibitors and bile acid sequestrants are weight-neutral. Liraglutide and exenatide appear to have similar effects on weight; however, recent research suggests a potentially greater effect of liraglutide on glycemic control compared to exenatide, when used as a second-line therapy. Mounting evidence suggests that insulin detemir may provide the most favorable weight benefits of available insulins.

CONCLUSIONS

Weight-beneficial agents should be considered in patients, particularly obese patients, who fail to reach glycemic targets on metformin therapy. We propose the following treatment choices based on potential weight benefit and blood glucose increment: long-acting GLP-1 agonists (liraglutide), DPP-4 inhibitors, bile acid sequestrants, amylin analogs, and basal insulin for patients with elevated fasting plasma glucose; and short-acting (exenatide) or long-acting GLP-1 agonists, amylin analogs, DPP-4 inhibitors, acarbose, and bile acid sequestrants for patients with elevated postprandial glucose. The weight-sparing effects of insulin detemir, notably in patients with high body mass index, should also be considered when initiating insulin therapy.

A case of chronic hepatitis C developing insulin-dependent diabetes, thyroid autoimmunity and stiff-person syndrome as complications of interferon therapy

We describe the case of a 66-year-old man with chronic hepatitis C who developed type 1 diabetes mellitus (T1DM) and thyroid autoimmunity during Interferon alpha (INFalpha) therapy and then stiff-person syndrome (SPS). This is the first reported case in which SPS has appeared as complication of IFNalpha therapy.

Effect of carbohydrate counting and medical nutritional therapy on glycaemic control in Type 1 diabetic subjects: a pilot study

AIMS

The effect of a balanced, carbohydrate-counting diet on glycaemic control in Type 1 diabetic subjects is unclear. Our aim was to determine its effect in a small, pilot trial.

METHODS

We randomized 256 Type 1 diabetic subjects to a Nutritional Education Programme (group A) or not (group B). Weight, body mass index, glycated haemoglobin (HbA1c), lipid profile, urate, creatinine, microalbuminuria and daily insulin requirements were measured at baseline and at the end of the study (9 months). During the study, the number of hypoglycaemic events (blood glucose<3.9 mmol/l) was also measured.

RESULTS

Compared with group B, group A showed: (i) a reduction in HbA1c (group A: 7.8+/-1.3-7.4+/-0.9%; group B: 7.5+/-0.8-7.5+/-1.1%; P<0.01); (ii) less hypoglycaemic events (4% vs. 7%; P<0.05); (iii) a reduction in dose of rapid insulin analogues (23.5+/-10.9 vs. 27.7+/-17.1 IU/24 h; P=0.03). No other between-group changes were observed.

CONCLUSIONS

This study shows the importance of medical nutritional therapy on glycaemic control in Type 1 diabetic subjects.

Similar cardiac remodelling after transcatheter atrial septal defect closure in children and young adults

OBJECTIVE

To study the cardiac geometric changes after transcatheter closure of large atrial septal defects (ASDs) according to patient age at the time of the procedure.

DESIGN

Prospective echocardiographic follow-up study.

SETTING

Tertiary referral centre.

PATIENTS AND INTERVENTION

25 asymptomatic patients younger than 16 years (median 8 years; group 1) and 21 asymptomatic adults (median 38 years; group 2) underwent percutaneous closure of large ASD with the Amplatzer septal occluder device (mean 25 (SD 7) mm).

MAIN OUTCOME MEASURES

Cardiac remodelling was assessed by M mode and two dimensional echocardiography one and six months after ASD closure.

RESULTS

By six months, right atrial volume decreased from 31 (15) to 19 (5) ml/m(2) (p < 0.001) and right ventricular (RV) transverse diameter decreased from 29.8 (8.6) to 23.2 (5.6) mm/m(2) (p < 0.001). Conversely, left atrial volume did not change significantly (from 18 (6) to 20 (6) ml/m(2), NS) and left ventricular (LV) transverse diameter increased from 27.8 (6.4) to 31.8 (7.3) mm/m(2) (p < 0.05). Ventricular remodelling resulted in an RV:LV diameter ratio decrease from 1.1 (0.2) to 0.7 (0.1) (p < 0.001). The magnitude and time course of cardiac remodelling did not differ significantly between the age groups. Indeed, right atrial volume decreased by 33 (26)% versus 37 (23)%, RV diameter decreased by 26 (10)% versus 20 (13)%, LV diameter increased by 17 (15)% versus 15 (10)%, and RV:LV diameter ratio decreased by 36 (8)% versus 27 (15)% in groups 1 and 2, respectively.

CONCLUSIONS

Cardiac remodelling after percutaneous ASD closure seems to be independent of the patient's age at the time of the procedure up to early adulthood. Thus, postponing ASD closure for a few years may be a reasonable option for potentially suitable asymptomatic children.

Effects of coexisting hypertension and type II diabetes mellitus on arterial stiffness

Hypertension (HT) is frequently associated with diabetes mellitus (DM) and its prevalence doubles in diabetics compared to the general population. This high prevalence is associated with increased stiffness of large arteries, which often precedes macrovascular events. The aim of our study was to evaluate the influence of HT and type II DM on aortic stiffness in patients with one disease or the other compared to those with both HT and type II DM. We studied 220 patients, 50 with type II DM (Group A), 50 with HT (Group B), 85 with both diseases (Group C), and 35 healthy subjects (HS). Regional arterial stiffness was assessed by automatic measurement of the carotid-femoral pulse wave velocity (PWV). For each patient, we evaluated: age, sex, body mass index, smoking habit, heart rate, SBP/DBP, pulse pressure (PP), mean BP, fasting glucose, lipid profile, uric acid, and fibrinogen. Group C had significantly more women and non smokers and the highest PP (61+/-14 mmHg). Of biochemical parameters, only fibrinogen was higher in Group A and in Group C (P<0.01 and P<0.001, respectively). Group C had a significantly higher PWV than the other four groups (P<0.0001). Stepwise forward regression analysis showed that fasting glucose was the first independent determinant of PWV (P<0.0001). In conclusion, this study shows that patients with DM and HT have higher arterial stiffness compared to HS and those with one disease or the other. Fasting glucose is the major independent determinant of PWV, which may be used as a relevant tool to assess the influence of cardiovascular risk factors on arterial stiffness in high-risk patients.

[Microcalcification and breast pathology: differential diagnosis and oncogenic risk assessment]

Breast cancer is one of the first cause of death in women. The investigation and the study of microcalcifications can discover about half of hidden breast carcinomas and this is an excellent help for the diagnosis. The aim of this study is to give some guidelines for a correct interpretation of these microcalcifications.

Chronic taurine supplementation ameliorates oxidative stress and Na+ K+ ATPase impairment in the retina of diabetic rats

This study evaluates the effect of 4 months supplementation with 2% and 5% taurine (w/w) on the retina of diabetic rats. In non-diabetic rats, taurine does not modify glycemia, body weight, retinal conjugated dienes (CD), lipid hydroperoxide (LP), and Na(+)K(+)ATPase activity. In diabetic rat, at 2, 4, 8, 16 weeks following the onset of diabetes, retinal CD and LP are significantly and progressively increased, while pump activity is gradually and significantly reduced. In taurine supplemented diabetic rats, glycemia is not affected but lipid peroxidation is significantly decreased. Finally, taurine preserves ATPase activity being 5% more effective than 2% taurine. We conclude that taurine supplementation ameliorates biochemical retinal abnormalities caused by diabetes, thereby suggesting that taurine may have a role in the prevention of retinal changes in diabetes.

[Catamenial epilepsy]

Many women with epilepsy report changes in seizures frequency in relationship to their menstrual cycle. Evidence from animal experiments and studies in humans have demonstrated an ovarian steroid hormone effect on neuronal excitability. The entity of the problem and its treatment have yet to be systematically evaluated. Is important to clarify the etiology and pathogenesis of catamenial fluctuations in seizure frequency and to outline optimal management strategies.

[Helicobacter pylori and gastric cancer. The incidence of infection in personal experience]

BACKGROUND

Helicobacter pylori is an identified carcinogen for gastric cancer, but the underlying mechanisms remain to be defined. The aim of this study is to analyze the incidence of Hp infection in our series of patients with gastric carcinoma.

METHODS

Between 1988 and 1998, 60 patients with diagnosis of gastric adenocarcinoma underwent partial or total gastrectomy. Forty-one were males and 19 females with an average age of 62 years (range 36-79). Twenty-seven cancers (45%) were localized in the lower third of the stomach, 17 (28%) in the middle third and eight (13%) in the upper third or cardias. In six patients (10%) the tumor was multicentric, while a recurrence on gastric stump after subtotal gastrectomy was present in two cases (3%). According to Lauren's criteria 39 cancers (65%) were of intestinal type, 16 (27%) of diffuse type and five (8%) of mixed type. The histologic preparations have been re-examined in order to verify the presence or not of Hp on gastric mucosa around neoplasm.

RESULTS

Hp was found in 35 (58%) of the analyzed specimens and therefore a significant percentage of patients was Hp-positive at the time of diagnosis and surgery. Between 35 Hp-positive samples, 24 were adenocarcinomas of intestinal type, nine of diffuse type and two of mixed type, with a prevalence of Hp in intestinal type cancer.

CONCLUSIONS

This study confirmed the high incidence of Hp infection in patients with gastric carcinoma, particularly in those with intestinal type cancer.

[Bacterial vaginosis and pregnancy]

Premature rupture of membranes (PROM) occurs in approximately 5-10% of all pregnancies and is implicated in approximately one third of preterm births. PROM is associated with increased risks of perinatal as well as maternal morbidity and mortality at every gestational age. Much information suggest that the presence of bacterial vaginosis may be implicated in the occurrence of PROM and subsequent preterm delivery in significant numbers of pregnant women. We will briefly review clinical and pathophysiologic information linking bacterial vaginosis and PROM.

Educational level and hypertension: how socioeconomic differences condition health care

This is the first European study that has evaluated educational level in a large sample of hypertensive outpatients. We established the educational level of the hypertensive outpatients in our unit, and determined whether the awareness of hypertension and its organ damage was education-related. We analysed data from 812 consecutive outpatients (378 men, mean age 50 +/- 10 years) with essential stage I-II hypertension. Subjects were subdivided into two categories: group A subjects were highly educated; group B subjects had a little education. Data were compared with educational level from the 1991 population census for the Campania region (ISTAT data) and with 200 type 2 diabetes patients (96 men, mean age 51 +/- 9 years) from the nearest diabetes unit. For each hypertensive patient we considered clinical, echocardiographic and biochemical parameters. Data from the last census showed a high percentage (80%) of subjects with low education. The percentage of type 2 diabetic patients with little education was high (190 patients, 95%). Conversely, it is somewhat surprising that most hypertensive patients reached high standards of education and worked at sedentary jobs (group A: 736 patients, 91%; P < 0.0001). Multivariate analysis showed that only diastolic blood pressure (P = 0.03) was independently associated with low educational level. Compared to diabetes, hypertension and its risk factors are relatively unknown to people with little education. Education is associated with greater health care and awareness that may overcome the risk related to low physical activity. Thus, we stress the importance of a sound health policy able to reach out to the uneducated and make them aware of hypertension and the health care services available to them.

[Asymptomatic bacteriuria in pregnancy]

Pregnancy is a predisposing factor for urinary tract infection and pregnant women suffering from this pathology are exposed to dangerous risks which may condition maternal wellbeing and fetal prognosis. Asymptomatic bacteriuria is the common bacterial infection requiring medical treatment in pregnancy. Diagnosis and treatment of asymptomatic bacteriuria is important as approximately 20-40% of these women, if untreated during pregnancy, will develop a symptomatic urinary tract infection.

Inhibition of protein farnesylation enhances the chemotherapeutic efficacy of the novel geranylgeranyltransferase inhibitor BAL9611 in human colon cancer cells

Proteins belonging to the ras superfamily are involved in cell proliferation of normal and neoplastic tissues. To be biologically active, they require post-translational isoprenylation by farnesyl-transferase and geranylgeranyl-transferase. Enzyme inhibition by drugs may thus represent a promising approach to the treatment of cancer. Therefore, the combined effect of BAL9611, a novel inhibitor of geranylgeranylation, and manumycin, a farnesyl-transferase inhibitor, was evaluated on the SW620 human colon cancer cell line which harbours a mutated K-ras gene. BAL9611 and manumycin dose-dependently inhibited SW620 cell growth with 50% inhibitory concentration (IC(50)) of 0.47 +/- 0.03 and 5.24 +/- 1.41 microM (mean +/- SE), respectively. The isobologram analysis performed at the IC(50)level revealed that the combined treatment was highly synergistic with respect to cell growth inhibition. BAL9611 and manumycin were able to inhibit the geranylgeranylation of p21rhoA and farnesylation of p21ras; both drugs inhibited p42ERK2/MAPK phosphorylation, but their combination was more effective than either drug alone. Moreover, the enhanced inhibition of cell growth in vitro by the BAL9611-manumycin combination was also observed in vivo in CD nu/nu female mice xenografted with SW620 tumours. Finally, both drugs were able to induce cell death by apoptosis in vitro and in vivo, as demonstrated by perinuclear chromatin condensation, cytoplasm budding and nuclear fragmentation, and interoligonucleosomal DNA digestion. In conclusion, the inhibition of protein farnesylation enhances the chemotherapeutic effect of BAL9611 in vitro and in vivo in a synergistic fashion, as a result of the impairment of post-translational isoprenylation of proteins and phosphorylation of p42ERK2/MAPK, whose activation is associated with post-translational geranylgeranylation and farnesylation of p21rhoA and p21ras.

[Prognosis and treatment of cervix uteri carcinoma in pregnancy]

Carcinoma of the cervix is tha most common ginecologic cancer found during pregnancy. Management and treatment of this condition depend on cancer stage and estimated gestational age. Pregnancy represents an ideal time for cervical cancer screening, and all pregnant women presenting for prenatal care should be carefully examinated. The prognosis for pregnant women is similar to that for non-pregnant one. The aim of this study is to review the incidence, treatment and prognosis of this condition during pregnancy.

[Epilepsy and pregnancy]

Epilepsy is one of the most common pre-existing neurologic disorders encountered by the obstetrician (1) and pregnant women with epilepsy constitute 0.5% of all pregnancies (2). Pregnant women with epilepsy are at risk for a variety of complications (3). Pregnancy may influence the course of epilepsy and epilepsy and antiepileptic drug therapy may have an impact on the course of pregnancy and pregnancy outcome. This study represents a retrospective analysis of 40 pregnant patients with epilepsy.

[Etiology and epidemiology of extrauterine pregnancy]

In the last years, ectopic pregnancy has become a frequent problem, especially in the industrialized countries. Women aged 30-40 years are mostly affected. Infact, in this ten-years period, more and more women feel the desire of pregnancy at ripe age, first of all because of their job. This study shows 136 cases of extrauterine pregnancy, observed at our hospital, I and II Institute of Obstetric and Gynecological Clinic of "Policlinico Umberto I" in Rome from January 1997 to December 1999. The object of this analysis is to determine the characteristics and ethiologic factors of this pathology.

Blunted erythropoietin response to anemia in patients with Type 1 diabetes

BACKGROUND

It is known that patients with renal failure have normochromic normocytic anemia due to impaired endogenous erythropoietin (EPO) synthesis. The aim of this work was to determine whether low serum erythropoietin (s-EPO) levels play a role in the pathogenesis of anemia in patients with Type 1 diabetes without overt nephropathy.

METHODS

We included in the study 13 patients with Type 1 diabetes whose Hb levels were <11 g/dl. Blood cell count, s-EPO, urinary albumin excretion rate (AER), HbA(1c), glomerular filtration rate, serum iron, serum ferritin, the presence of neuropathy, retinopathy and nephropathy were determined.

RESULTS

Ten out of 13 patients with anemia (77%) had a blunted EPO response to anemia. All ten patients with low EPO levels had autonomic neuropathy; five had clinical nephropathy but with serum creatinine<1.6 mg/dl. Three patients were treated with rHuEPO and showed an improvement in their anemia after treatment.

CONCLUSION

The majority of patients with Type 1 diabetes who had anemia also had low EPO levels. The pathogenesis of this phenomenon is probably multifactorial. Autonomic neuropathy appears to play a role, but it is not sufficient, per se, to be the only cause. Dysautonomia might enhance the effect of renal damage.

Schizophrenic symptoms and SPECT abnormalities in a coeliac patient: regression after a gluten-free diet

A 33-year-old patient, with pre-existing diagnosis of 'schizophrenic' disorder, came to our observation for severe diarrhoea and weight loss. Use of single photon emission computed tomography, (99mTc)HMPAO SPECT, demonstrated hypoperfusion of the left frontal brain area, without evidence of structural cerebral abnormalities. Jejunal biopsy showed villous atrophy. Antiendomysial antibodies were present. A gluten-free diet was started, resulting in a disappearence of psychiatric symptoms, and normalization of histological duodenal findings and of (99mTc)HMPAO SPECT pattern. This is the first case in which, in an undiagnosed and untreated coeliac patient with psychiatric manifestations, the (99mTc)HMPAO SPECT demonstrated a dysfunction of frontal cortex disappearing after a gluten-free diet.