An adversarial learning approach to generate pressure support ventilation waveforms for asynchrony detection

BACKGROUND AND OBJECTIVE

Mechanical ventilation is a life-saving treatment for critically-ill patients. During treatment, patient-ventilator asynchrony (PVA) can occur, which can lead to pulmonary damage, complications, and higher mortality. While traditional detection methods for PVAs rely on visual inspection by clinicians, in recent years, machine learning models are being developed to detect PVAs automatically. However, training these models requires large labeled datasets, which are difficult to obtain, as labeling is a labour-intensive and time-consuming task, requiring clinical expertise. Simulating the lung-ventilator interactions has been proposed to obtain large labeled datasets to train machine learning classifiers. However, the obtained data lacks the influence of different hardware, of servo-controlled algorithms, and different sources of noise. Here, we propose VentGAN, an adversarial learning approach to improve simulated data by learning the ventilator fingerprints from unlabeled clinical data.

METHODS

In VentGAN, the loss functions are designed to add characteristics of clinical waveforms to the generated results, while preserving the labels of the simulated waveforms. To validate VentGAN, we compare the performance for detection and classification of PVAs when training a previously developed machine learning algorithm with the original simulated data and with the data generated by VentGAN. Testing is performed on independent clinical data labeled by experts. The McNemar test is applied to evaluate statistical differences in the obtained classification accuracy.

RESULTS

VentGAN significantly improves the classification accuracy for late cycling, early cycling and normal breaths (p< 0.01); no significant difference in accuracy was observed for delayed inspirations (p = 0.2), while the accuracy decreased for ineffective efforts (p< 0.01).

CONCLUSIONS

Generation of realistic synthetic data with labels by the proposed framework is feasible and represents a promising avenue for improving training of machine learning models.

High clonality of Mycobacterium avium subsp. paratuberculosis field isolates from red deer revealed by two different methodological approaches of comparative genomic analysis

Mycobacterium avium subsp. paratuberculosis (MAP) is the aetiological agent of paratuberculosis (Johne's disease) in both domestic and wild ruminants. In the present study, using a whole-genome sequence (WGS) approach, we investigated the genetic diversity of 15 Mycobacterium avium field strains isolated in the last 10 years from red deer inhabiting the Stelvio National Park and affected by paratuberculosis. Combining de novo assembly and a reference-based method, followed by a pangenome analysis, we highlight a very close relationship among 13 MAP field isolates, suggesting that a single infecting event occurred in this population. Moreover, two isolates have been classified as Mycobacterium avium subsp. hominissuis, distinct from the other MAPs under comparison but close to each other. This is the first time that this subspecies has been found in Italy in samples without evident epidemiological correlations, having been isolated in two different locations of the Stelvio National Park and in different years. Our study highlights the importance of a multidisciplinary approach incorporating molecular epidemiology and ecology into traditional infectious disease knowledge in order to investigate the nature of infectious disease in wildlife populations.

A roadmap of tissue culture and biotechnology in European hazelnut (Corylus avellana L.)

The increasing interest in European hazelnut (Corylus avellana L.) cultivation registered in the last years has led to a significant increase in worldwide hazelnut growing areas, also involving regions characterized by a marginal presence of hazelnut orchards. Despite this increasement, world production still relies on the cultivation of few varieties, most of which are particularly suitable to the environment where they have been selected. Therefore, it is necessary to develop new cultivars with high environmental plasticity capable of providing constant and high-quality productions in the new environments and under the climatic change conditions of traditional growing areas. Over the years, many molecular markers for genetic breeding programs have been developed and omics sciences also provided further information about the genetics of this species. These data could be of support to the application of new plant breeding techniques (NPBTs), which would allow the development of cultivars with the desired characteristics in a shorter time than traditional techniques. However, the application of these methodologies is subordinated to the development of effective regeneration protocols which, to date, have been set up exclusively for seed-derived explants. A further aspect to be exploited is represented by the possibility of cultivating hazelnut cells and tissues in vitro to produce secondary metabolites of therapeutic interest. This review aims to consolidate the state of the art on biotechnologies and in vitro culture techniques applied on this species, also describing the various studies that over time allowed the identification of genomic regions that control traits of interest.

Evaluation of the accuracy of established patient inspiratory effort estimation methods during mechanical support ventilation

There is a clinical need for monitoring inspiratory effort to prevent lung- and diaphragm injury in patients who receive supportive mechanical ventilation in an Intensive Care Unit. Different pressure-based techniques are available to estimate this inspiratory effort at the bedside, but the accuracy of their effort estimation is uncertain since they are all based on a simplified linear model of the respiratory system, which omits gas compressibility of air, and the viscoelasticity and nonlinearities of the respiratory system. The aim of this in-silico study was to provide an overview of the pressure-based estimation techniques and to evaluate their accuracy using a more sophisticated model of the respiratory system and ventilator. The influence of the following parameters on the accuracy of the pressure-based estimation techniques was evaluated using the in-silico model: 1) the patient's respiratory mechanics 2) PEEP and the inspiratory pressure of the ventilator 3) gas compressibility of air 4) viscoelasticity of the respiratory system 5) the strength of the inspiratory effort. The best-performing technique in terms of accuracy was the whole breath occlusion. The average error and maximum error were the lowest for all patient archetypes. We found that the error was related to the expansion of gas in the breathing set and lungs and respiratory compliance. However, concerns exist that other factors not included in the model, such as a changed muscle-force relation during an occlusion, might influence the true accuracy. The estimation techniques based on the esophageal pressure showed an error related to the viscoelastic element in the model which leads to a higher error than the occlusion. The error of the esophageal pressure-based techniques is therefore highly dependent on the pathology of the patient and the settings of the ventilator and might change over time while a patient recovers or becomes more ill.

3D printing and 3D bioprinting technology in medicine: ethical and legal issues

Abstract

There has been a surge of interest in new technologies in medicine because of their promising clinical applications. Extensive research on additive manufacturing and its applications in the medical field has been carried out with good results and very high expectations. Due to their disruptive nature and potential, 3D printing and even more 3D bioprinting raise many ethical and safety concerns that need to be adequately addressed to provide good regulation before entering clinical practice. This article aims to highlight the general ethical concerns associated with the use of additive manufacturing in medicine and the lack of current international regulatory directives to guide these experiments. Transparency about how these new medical devices are regulated and approved is a fundamental requirement to promote and improve public trust, efficiency, safety and quality.

The number of risk factors not at target is associated with cardiovascular risk in a type 2 diabetic population with albuminuria in primary cardiovascular prevention. Post-hoc analysis of the NID-2 trial

Background

Nephropathy in Diabetes type 2 (NID-2) study is an open-label cluster randomized clinical trial that demonstrated that multifactorial intensive treatment reduces Major Adverse Cardiac Events (MACEs) and overall mortality versus standard of care in type 2 diabetic subjects with albuminuria and no history of cardiovascular disease. Aim of the present post-hoc analysis of NID- 2 study is to evaluate whether the number of risk factors on target associates with patient outcomes.

Methods

Intervention phase lasted four years and subsequent follow up for survival lasted 10 years. To the aim of this post-hoc analysis, the whole population has been divided into 3 risk groups: 0–1 risk factor (absent/low); 2–3 risk factors (intermediate); 4 risk factors (high). Primary endpoint was a composite of fatal and non-fatal MACEs, the secondary endpoint was all-cause death at the end of the follow-up phase.

Results

Absent/low risk group included 166 patients (52.4%), intermediate risk group 128 (40.4%) and high-risk group 23 (7.3%). Cox model showed a significant higher risk of MACE and death in the high-risk group after adjustment for confounding variables, including treatment arm (HR 1.91, 95% CI 1.04–3.52, P = 0.038 and 1.96, 95%CI 1.02–3.8, P = 0,045, respectively, vs absent/low risk group).

Conclusions

This post-hoc analysis of the NID-2 trial indicates that the increase in the number of risk factors at target correlates with better cardiovascular-free survival in patients with type 2 diabetes at high CV risk.

Clinical Trial Registration

ClinicalTrials.gov number, NCT00535925. https://clinicaltrials.gov/ct2/show/NCT00535925

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01674-7.

Death occurred due to undiagnosed systemic amyloidosis: a case report

Amyloidosis is a disorder related to errors in protein folding. We present a clinical case of systemic amyloidosis manifesting as hypotension, tachycardia, pain, weight loss, asthenia, anorexia, dysphagia, and mood deflection in a 49-year-old-year-old woman with a previous clinical history of articular and muscular pain, correlated to suspected seronegative arthritis. The blood test revealed kidney insufficiency, an electrocardiogram identified low voltages of the peripheral leads and T waves anomalies. A serum protein electrophoresis revealed the presence of high levels of monoclonal kappa free chains. The woman started to have a sense of suffocation, and after one week she was found dead in her bed. After the autopsy, the results of Congo red staining of the myocardium were characteristic of amyloid. According to the autoptic and the histological examination, death occurred due to acute cardiac and respiratory arrest secondary to amyloid cardiomyopathy in a patient with undiagnosed systemic amyloidosis.

Less is more: natural variation disrupting a miR172 gene at the di locus underlies the recessive double-flower trait in peach (P. persica L. Batsch)

BACKGROUND

With the domestication of ornamental plants, artificial selective pressure favored the propagation of mutations affecting flower shape, and double-flower varieties are now readily available for many species. In peach two distinct loci control the double-flower phenotype: the dominant Di2 locus, regulated by the deletion of the binding site for miR172 in the euAP2 PETALOSA gene Prupe.6G242400, and the recessive di locus, of which the underlying factor is still unknown.

RESULTS

Based on its genomic location a candidate gene approach was used to identify genetic variants in a diverse panel of ornamental peach accessions and uncovered three independent mutations in Prupe.2G237700, the gene encoding the transcript for microRNA miR172d: a ~5.0 Kb LTR transposable element and a ~1.2 Kb insertion both positioned upstream of the sequence encoding the pre-miR172d within the transcribed region of Prupe.2G237700, and a ~9.5 Kb deletion encompassing the whole gene sequence. qRT-PCR analysis confirmed that expression of pre-miR172d was abolished in di/di genotypes homozygous for the three variants.

CONCLUSIONS

Collectively, PETALOSA and the mutations in micro-RNA miR172d identified in this work provide a comprehensive collection of the genetic determinants at the base of the double-flower trait in the peach germplasms.

Complete genome assembly of the levan-positive strain PVFi1 of Pseudomonas savastanoi pv. savastanoi isolated from olive knots in Central Italy

Pseudomonas savastanoi pv. savastanoi, the causal agent of olive knot disease, is a fluorescent Gram-negative bacterium classified, according to the specific LOPAT profile, as Ib. However, during the 90s, a number of atypical non-fluorescent levan-positive strains of Pseudomonas savastanoi pv. savastanoi have been unexpectedly isolated from olive knots in Central Italy. Since its first report, several studies were conducted on this species variant, but its genome sequence has never been reported. The complete genome sequence and two additional plasmids of PVFi1, a representative strain, were here obtained using a hybrid sequencing approach with both Oxford Nanopore Technology and Illumina sequencing. A thorough genomic analysis unravelled several genetic features of this peculiar strain, showing a transposase insertion downstream a fragmented copy of the levansucrase gene. The same features were previously reported on levan-negative Pseudomonas savastanoi pv. savastanoi strains. In addition, a second copy of the levansucrase gene fully equipped for a gene expression and comparable to the levan-positive Pseudomonas savastanoi pv. glycinea, may explain the levan-positive test. This result provides a solid genetic demonstration that the bacterial species Pseudomonas savastanoi contains either levan-positive or levan-negative strains, providing insights for an update of the related LOPAT classification.

A Model-based Approach to Generating Annotated Pressure Support Waveforms

During pressure support ventilation, every breath is triggered by the patient. Mismatches between the patient and the ventilator are called asynchronies. It has been reported that large numbers of asynchronies may be harmful and may lead to increased mortality. Automatic asynchrony detection and classification, with subsequent feedback to clinicians, will improve lung ventilation and, possibly, patient outcome. Machine learning techniques have been used to detect asynchronies. However, large, diverse and high-quality training and verification data sets are needed. In this work, we propose a model for generating a large, realistic, labeled, synthetic dataset for training and testing machine learning algorithms to detect a wide variety of asynchrony types. Next to a morphological evaluation of the obtained waveforms, validation of the proposed model includes a test with a machine learning algorithm trained on clinical data.

Identification and Molecular Characterization of a Novel Hordeivirus Associated With Yellow Mosaic Disease of Privet (Ligustrum vulgare) in Europe

Wild plants serve as a large reservoir of known and yet-unknown viruses and as a source of viral pathogens of cultivated plants. Yellow mosaic disease of forest shrub Ligustrum vulgare (privet) was recurrently observed in Europe for more than 100 years. Using a universal virus identification approach based on deep sequencing and de novo assembly of viral small interfering (si)RNAs we identified a causative agent of this disease in Switzerland and reconstructed its complete 3-segmented RNA genome. Notably, a short 3'-terminal common region (CR) attached to each segment via a ∼53-71 nucleotide poly(A) tract, as determined by RT-PCR sequencing, was initially identified as an orphan siRNA contig with conserved tRNA-like secondary structure. Phylogenomic analysis classified this virus as a novel member in the genus Hordeivirus of family Virgaviridae, which we named ligustrum mosaic virus (LigMV). Similar to other hordeiviruses, LigMV formed rod-shape virions (visualized by electron microscopy), was transmitted through seeds and could also be mechanically transmitted to herbaceous hosts Chenopodium quinoa and Nicotiana benthamiana. Blot hybridization analysis identified genomic and subgenomic RNAs, sharing the 3'-CR and likely serving as monocistronic mRNAs for seven evolutionarily-conserved viral proteins including two subunits of viral RNA-dependent RNA polymerase, coat protein, triple gene block proteins mediating viral movement and cysteine-rich suppressor of RNA silencing. Analysis of size, polarity, and hotspot profiles of viral siRNAs suggested that they are produced by the plant antiviral Dicer-like (DCL) proteins DCL2 and DCL4 processing double-stranded intermediates of genomic RNA replication. Whole genome sequencing of French and Austrian isolates of LigMV revealed its genetic stability over a wide geographic range (>99% nucleotide identity to Swiss isolates and each other), suggesting its persistence and spread in Europe via seed dispersal.

Role of post mortem CT (PMCT) in high energy traumatic deaths

BACKGROUND

Post Mortem Computed Tomography (PMCT) is being increasingly implemented in forensic field and could be an adjuvant to classic autopsies. In this study we evaluated the feasibility of complementation of conventional autopsy in trauma victims with PMCT.

MATERIALS AND METHODS

A total of 21 subjects, who had sustained various types of blunt high-energy trauma, were selected from the casuistry of the Section of Legal Medicine at University of Pisa: before autopsy, a PMCT examination (Toshiba Aquilion 16 CT scanner) was performed, and after the acquisition of the raw images, MPR and VR reconstructions were performed with dedicated software.

RESULTS

PMCT is more sensitive than conventional autopsy in detecting skeletal injuries, whilst autopsy constitutes the method of choice for the detection of thoracic and abdominal visceral injuries.

CONCLUSIONS

PMCT should be considered a useful tool in addition to conventional autopsy in evaluating trauma victims: it detects further bone fractures in body parts difficult to investigate during autopsy (i.e. posterior regions), facilitating the pathologist in the reconstruction of events and in determining the cause of death.

Draft Genome Sequence of a New Fusarium Isolate Belonging to Fusarium tricinctum Species Complex Collected From Hazelnut in Central Italy

In summer 2019, during a survey on the health status of a hazelnut orchard located in the Tuscia area (the province of Viterbo, Latium, Italy), nuts showing symptoms, such as brown-grayish spots at the bottom of the nuts progressing upward to the apex, and necrotic patches on the bracts and, sometimes, on the petioles, were found and collected for further studies. This syndrome is associated with the nut gray necrosis (NGN), whose main causal agent is Fusarium lateritium. Aiming to increase knowledge about this fungal pathogen, the whole-genome sequencing of a strain isolated from symptomatic hazelnut was performed using long Nanopore reads technology in combination with the higher precision of the Illumina reads, generating a high-quality genome assembly. The following phylogenetic and comparative genomics analysis suggested that this isolate is caused by the F. tricinctum species complex rather than F. lateritium one, as initially hypothesized. Thus, this study demonstrates that different Fusarium species can infect Corylus avellana producing the same symptomatology. In addition, it sheds light onto the genetic features of the pathogen in subject, clarifying facets about its biology, epidemiology, infection mechanisms, and host spectrum, with the future objective to develop specific and efficient control strategies.

Method for measurement of arterial compliance by fusion of oscillometry and pulse wave velocity

Up until now estimation of arterial compliance has been performed either by analysis of arterial pressure changes with respect to volume changes or by inference based on pulse wave velocity (PWV). In this study we demonstrate the possibility of an approach to assess arterial compliance by fusing the two information sources namely the pressure/volume relationship obtained from oscillography and PWV data. The goal is to assess arterial properties easily and robustly, enhancing current hemodynamic monitoring. The approach requires as input signals: an electrocardiogram (ECG), a photo- plethysmogram (PPG) and the arterial oscillation as measured during non-invasive blood pressure measurements based on oscillometry with a cuff. These signals are fused by an algorithm using Bayesian principles underpinned by a physiological model. In our simulations, we demonstrate the feasibility to infer arterial compliance by our proposed strategy. A very first measurement on a healthy volunteer supports our findings from the simulation.Clinical Relevance- Arterial compliance/stiffness is recognized as a key hemodynamic parameter, which is not easily accessible and not a standard parameter currently. The presented method and obtained results are encouraging for future research in this area.

A machine learning method for automatic detection and classification of patient-ventilator asynchrony

Patients suffering from respiratory failure are often put on assisted mechanical ventilation. Patient-ventilator asynchrony (PVA) can occur during mechanical ventilation, which cause damage to the lungs and has been linked to increased mortality in the intensive care unit. In current clinical practice PVA is still detected using visual inspection of the air pressure, flow, and volume curves, which is time-consuming and sensitive to subjective interpretation. Correct detection of the patient respiratory efforts is needed to properly asses the type of asynchrony. Therefore, we propose a method for automatic detection of the patient respiratory efforts using a one-dimensional convolution neural network. The proposed method was able to detect patient efforts with a sensitivity and precision of 98.6% and 97.3% for the inspiratory efforts, and 97.7% and 97.2% for the expiratory efforts. Besides allowing detection of PVA, combining the estimated timestamps of patient's inspiratory and expiratory efforts with the timings of the mechanical ventilator further allows for classification of the asynchrony type. In the future, the proposed method could support clinical decision making by informing clinicians on the quality of ventilation and providing actionable feedback for properly adjusting the ventilator settings.

A new inclusive MLVA assay to investigate genetic variability of Xylella fastidiosa with a specific focus on the Apulian outbreak in Italy

The Olive Quick Decline Syndrome by Xylella fastidiosa subspecies pauca is among the most severe phytopathological emergencies nowadays. In few years, the outbreak devastated olive groves in Apulia (Italy), potentially endangering the entire Mediterranean basin. This research aimed to develop a multiple locus VNTR analysis assay, a molecular tool to differentiate between populations of the pathogen. It has already been successfully applied to different X. fastidiosa subspecies from various plant hosts. The previously published TR loci, together with a set of new design, have been tested in silico on the genome of the Apulian De Donno strain. The resulting selection of 37 TR loci was amplified on the genomic DNAs of the Apulian strains AND from representatives of X. fastidiosa subspecies, and directly on DNA extracted from infected plants. The assay clearly discerned among subspecies or even sequence types (ST), but also pointed out variants within the same ST so as to provide more detailed information on the dynamics and pathogen diffusion pathways. Its effective application even on total DNAs extracted from infected tissues of different host plants makes it particularly useful for large-scale screening of infection and for the strengthening of containment measures.

Virus Detection by High-Throughput Sequencing of Small RNAs: Large-Scale Performance Testing of Sequence Analysis Strategies

Recent developments in high-throughput sequencing (HTS), also called next-generation sequencing (NGS), technologies and bioinformatics have drastically changed research on viral pathogens and spurred growing interest in the field of virus diagnostics. However, the reliability of HTS-based virus detection protocols must be evaluated before adopting them for diagnostics. Many different bioinformatics algorithms aimed at detecting viruses in HTS data have been reported but little attention has been paid thus far to their sensitivity and reliability for diagnostic purposes. Therefore, we compared the ability of 21 plant virology laboratories, each employing a different bioinformatics pipeline, to detect 12 plant viruses through a double-blind large-scale performance test using 10 datasets of 21- to 24-nucleotide small RNA (sRNA) sequences from three different infected plants. The sensitivity of virus detection ranged between 35 and 100% among participants, with a marked negative effect when sequence depth decreased. The false-positive detection rate was very low and mainly related to the identification of host genome-integrated viral sequences or misinterpretation of the results. Reproducibility was high (91.6%). This work revealed the key influence of bioinformatics strategies for the sensitive detection of viruses in HTS sRNA datasets and, more specifically (i) the difficulty in detecting viral agents when they are novel or their sRNA abundance is low, (ii) the influence of key parameters at both assembly and annotation steps, (iii) the importance of completeness of reference sequence databases, and (iv) the significant level of scientific expertise needed when interpreting pipeline results. Overall, this work underlines key parameters and proposes recommendations for reliable sRNA-based detection of known and unknown viruses.

Small RNA-Omics for Virome Reconstruction and Antiviral Defense Characterization in Mixed Infections of Cultivated Solanum Plants

In plants, RNA silencing-based antiviral defense generates viral small RNAs (sRNAs) faithfully representing the viral genomes. We employed sRNA sequencing and bioinformatics (sRNA-omics) to characterize antiviral defense and to reconstruct the full genomic sequences and their variants in the evolving viral quasispecies in cultivated solanaceous plants carrying mixed infections. In naturally infected Solanum tuberosum (potato), one case study revealed a virome comprising Potato virus Y (genus Potyvirus) and Potato virus X (genus Potexvirus), which was reconstructed by de novo-assembling separate genome-size sRNA contigs. Another case study revealed a virome comprising NTN and O strains of Potato virus Y, whose sRNAs assembled in chimeric contigs, which could be disentangled on the basis of reference genome sequences. Both viromes were stable in vegetative potato progeny. In a cross-protection trial of Solanum lycopersicum (tomato), the supposedly protective mild strain CH2 of Pepino mosaic virus (genus Potexvirus) was tested for protection against strain LP of the same virus. Reciprocal mechanical inoculations eventually resulted in co-infection of all individual plants with CH2 and LP strains, reconstructed as separate sRNA contigs. LP invasions into CH2-preinfected plants and vice versa were accompanied by alterations of consensus genome sequences in viral quasispecies, indicating a potential risk of cross-protection measures. Additionally, the study also revealed, by reconstruction from sRNAs, the presence of the mechanically nontransmissible Southern tomato virus (genus Amalgavirus) in some plants. Our in-depth analysis of sRNA sizes, 5'-nucleotide frequencies and hotspot maps revealed similarities in sRNA-generating mechanisms in potato and tomato, differential silencing responses to virome components and potential for sRNA-directed cross-targeting between viral strains which could not, however, prevent the formation of stable viromes.

Emergence of a Latent Indian Cassava Mosaic Virus from Cassava Which Recovered from Infection by a Non-Persistent Sri Lankan Cassava Mosaic Virus

The major threat for cassava cultivation on the Indian subcontinent is cassava mosaic disease (CMD) caused by cassava mosaic geminiviruses which are bipartite begomoviruses with DNA A and DNA B components. Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) cause CMD in India. Two isolates of SLCMV infected the cassava cultivar Sengutchi in the fields near Malappuram and Thiruvananthapuram cities of Kerala State, India. The Malappuram isolate was persistent when maintained in the Madurai Kamaraj University (MKU, Madurai, Tamil Nadu, India) greenhouse, whereas the Thiruvananthapuram isolate did not persist. The recovered cassava plants with the non-persistent SLCMV, which were maintained vegetative in quarantine in the University of Basel (Basel, Switzerland) greenhouse, displayed re-emergence of CMD after a six-month period. Interestingly, these plants did not carry SLCMV but carried ICMV. It is interpreted that the field-collected, SLCMV-infected cassava plants were co-infected with low levels of ICMV. The loss of SLCMV in recovered cassava plants, under greenhouse conditions, then facilitated the re-emergence of ICMV. The partial dimer clones of the persistent and non-persistent isolates of SLCMV and the re-emerged isolate of ICMV were infective in Nicotiana benthamiana upon agroinoculation. Studies on pseudo-recombination between SLCMV and ICMV in N. benthamiana provided evidence for trans-replication of ICMV DNA B by SLCMV DNA A.

Viral protein suppresses oxidative burst and salicylic acid-dependent autophagy and facilitates bacterial growth on virus-infected plants

Virus interactions with plant silencing and innate immunity pathways can potentially alter the susceptibility of virus-infected plants to secondary infections with nonviral pathogens. We found that Arabidopsis plants infected with Cauliflower mosaic virus (CaMV) or transgenic for CaMV silencing suppressor P6 exhibit increased susceptibility to Pseudomonas syringae pv. tomato (Pst) and allow robust growth of the Pst mutant hrcC-, which cannot deploy effectors to suppress innate immunity. The impaired antibacterial defense correlated with the suppressed oxidative burst, reduced accumulation of the defense hormone salicylic acid (SA) and diminished SA-dependent autophagy. The viral protein domain required for suppression of these plant defense responses is dispensable for silencing suppression but essential for binding and activation of the plant target-of-rapamycin (TOR) kinase which, in its active state, blocks cellular autophagy and promotes CaMV translation. Our findings imply that CaMV P6 is a versatile viral effector suppressing both silencing and innate immunity. P6-mediated suppression of oxidative burst and SA-dependent autophagy may predispose CaMV-infected plants to bacterial infection.

Closed-form solution of the convolution integral in the magnetic resonance dispersion model for quantitative assessment of angiogenesis

Prostate cancer (PCa) diagnosis and treatment is still limited due to the lack of reliable imaging methods for cancer localization. Based on the fundamental role played by angiogenesis in cancer growth and development, several dynamic contrast enhanced (DCE) imaging methods have been developed to probe tumor angiogenic vasculature. In DCE magnetic resonance imaging (MRI), pharmacokinetic modeling allows estimating quantitative parameters related to the physiology underlying tumor angiogenesis. In particular, novel magnetic resonance dispersion imaging (MRDI) enables quantitative assessment of the microvascular architecture and leakage, by describing the intravascular dispersion kinetics of an extravascular contrast agent with a dispersion model. According to this model, the tissue contrast concentration at each voxel is given by the convolution between the intravascular concentration, described as a Brownian motion process according to the convective-dispersion equation, with the interstitium impulse response, represented by a mono-exponential decay, and describing the contrast leakage in the extravascular space. In this work, an improved formulation of the MRDI method is obtained by providing an analytical solution for the convolution integral present in the dispersion model. The performance of the proposed method was evaluated by means of dedicated simulations in terms of estimation accuracy, precision, and computation time. Moreover, a preliminary clinical validation was carried out in five patients with proven PCa. The proposed method allows for a reduction by about 40% of computation time without any significant change in estimation accuracy and precision, and in the clinical performance.

Cell fate following ER stress: just a matter of "quo ante" recovery or death?

The endoplasmic reticulum (ER) is a complex and multifunctional organelle. It is the intracellular compartment of protein folding, a complex task, both facilitated and monitored by ER folding enzymes and molecular chaperones. The ER is also a stress-sensing organelle. It senses stress caused by disequilibrium between ER load and folding capacity and responds by activating signal transduction pathways, known as unfolded protein response (UPR). Three major classes of transducer are known, inositol-requiring protein-1 (IRE1), activating transcription factor-6 (ATF6), and protein kinase RNA (PKR)-like endoplasmic reticulum kinase (PERK), which sense with their endoluminal domain the state of protein folding, although the exact mechanism(s) involved is not entirely clear. Depending on whether the homeostatic response of the UPR is successful in restoring an equilibrium between ER load and protein folding or not, the two possible outcomes of the UPR so far considered have been life or death. Indeed, recent efforts have been devoted to understand the life/death switch mechanisms. However, recent data suggest that what appears to be a pure binary decision may in fact be more complex, and survival may be achieved at the expenses of luxury cell functions, such as expression of differentiation genes.

Ophthalmological aspects of IBD

Ocular manifestations occur in 4-12% of patients with IBD. Uveitis and iritis are more frequently associated with ulcerative colitis while episcleritis is more common in Crohn's disease. Some ocular manifestations in IBD can be secondary to treatment and/or effects of the intestinal disease itself. The specific management of ocular manifestations in IBD requires the use of topical steroids and FANS, cycloplegics, systemic steroids or immunosuppressive drugs. When conventional therapies fail to control the ocular manifestations in IBD, the new biologic drugs can be considered as good alternative treatments. Early diagnosis and effective treatment may avoid the onset of severe and sometimes persisting complications. In some cases, a surgical approach is required to treat eye complications, i.e. cataract, and to improve the patient's quality of life.

Early detection of diabetic cardiomyopathy: usefulness of tissue Doppler imaging

OBJECTIVE

The aim of the study was to evaluate whether tissue Doppler imaging (TDI) detects a pre-clinical impairment of diastolic function in subjects with Type 2 diabetes with short duration of disease and normal cardiac function with conventional echocardiography (CE), and whether echocardiographic parameters are related to metabolic abnormalities.

PATIENTS AND METHODS

We studied 40 non-obese, normotensive, uncomplicated Type 2 diabetic subjects with short duration of disease and 20 control subjects. All participants underwent both CE and TDI echocardiography. With TDI, early velocity (Ea), atrial velocity (Aa), their ratio (Ea/Aa) and systolic velocity (Sa) were measured at the lateral corner of mitral annulus. Glycosylated haemoglobin, fasting plasma glucose and insulin were determined and homeostasis model assessment (HOMA-IR), as an index of insulin resistance, was calculated.

RESULTS

Cardiac function with CE was similar in the two groups. Using TDI, diabetic subjects showed a lower Ea velocity (15.5+/-3.9 vs. 19.4+/-3.5 cm/s, P<0.0001), an increased Aa velocity (15.5+/-2.4 vs. 14.1+/-2.4 cm/s, P<0.05) and a reduced Ea/Aa ratio (1.00+/-0.2 vs. 1.39+/-0.3, P<0.0001), compared with control subjects. Linear regression analysis in the diabetic group showed that only HOMA-IR was negatively associated with Ea/Aa ratio (P=0.026). No significant association was observed with other metabolic variables.

CONCLUSION

An early stage of diabetic cardiomyopathy can be evidenced by TDI in Type 2 diabetic subjects even in the presence of a normal cardiac function with CE. This abnormality is associated with insulin resistance.

Vestibular evaluation in Behçet's disease. Personal experience

Few reports have appeared in the literature concerning vestibular findings in Behçet's disease. In the present study, extensive vestibular testing, performed in 14 patients (8 male, 6 female; mean age: 32 years; range: 12-51) presenting definite Behçet's disease, revealed a high prevalence of central vestibular dysfunctions (78%). Data reported here suggest that an otoneurological evaluation of Behçet's disease patients may be helpful in identifying unexpected vestibular dysfunctions and central nervous system involvement different from the classical manifestations of the neuro-Behçet's syndrome.

[Treatment of curved canals: from stainless steel to nickel titanium]

Endodontic treatment of curved canals is always more difficult than straight canals, especially for the apical zone preparation: root canals may present several curvatures in different space directions. From an anatomical point of view root canals with accentuated curvatures are a very frequent event (more than we might think); radiological exams, in fact, give us only a 2D image, and we can observe mesial or distal curvatures but not those in the oral or buccal direction. However, all root canals have curvatures of some degrees; even those that appear straight. Because of this, endodontitis have made many attempts to overcome these problems and manage to have a good preparation in curve canal. The authors analyse all endodontic techniques (step back, step down, crown down, balanced forces) codified in the course of the years, to prepare curved canals; they both in shape or in materials. It's fundamental for the endodontist to have a specific technique to treat curved canals to allow a good, wide preparation; in this way it's possible to make a better and tridimensional filling of the endodontic space above all in the tipical zone.

Secondary prevention of coronary artery disease in high-risk diabetic patients

BACKGROUND AND AIM

To compare guideline implementation and the actual delivery of secondary prevention for coronary artery disease in the cohort of Italian diabetic patients enrolled in the DAI study.

METHODS AND RESULTS

The DAI study is a multicentre cohort study of the prevalence and incidence of macroangiopathic events among 19,570 type 2 diabetic patients attending 201 Diabetic Care Units. For this study, we selected 1,475 subjects with a history of myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty at enrollment. Only 25% of the coronary patients in secondary prevention were receiving lipid-lowering drugs, and 20% were receiving beta-blockers. None of the patients in 54/185 Diabetic Care Units were on statins, and none in 82/185 Units were on beta-blockers. Multivariate analysis showed a positive correlation between the number of treatments and the taking of statins, and a negative correlation with age.

CONCLUSION

Our data highlight a gap between the therapeutic guidelines and actual treatment, with wide variability in the delivery of secondary prevention across Units. The out-of-pocket cost of medication, daily treatment burden and geographic area can be ruled out as possible explanatory factors. Physicians' prescription attitudes may be a possible reason.

Selected food intake and risk of multiple pregnancies

In order to explore the association between multiple birth risk and diet, data were analysed from a case-control study on risk factors for multiple births conducted in Italy between 1988 and 1998. A total of 185 cases (median age 30 years) were interviewed: 36 women delivered monozygotic and 149 delivered spontaneous dizygotic multiple births. The control group comprised 498 women who gave birth at term (>37 weeks gestation) to healthy infants on randomly selected days at the same clinic. Women were specifically excluded if they reported a history of multiple pregnancy or they had received treatment for infertility for the index pregnancy. No marked differences emerged in daily intake between cases and controls and a total of 35 foods items, including the major sources of beta-carotene, retinol, ascorbic acid, vitamin D, E, methionine folate and calcium in the Italian diet. Likewise intake of selected micronutrients was largely similar in dizygotic cases, monozygotic cases and controls, with the only exception of a slightly lower intake of folates in dizygotic pregnancies in comparison with controls: this difference was statistically significant (P < 0.05), but limited in quantitative terms (mean daily intake of folate 192.4, 183.2 and 191.4 microg respectively in monozygotic, dizygotic cases and controls). In conclusion, the results of this study do not support the role of diet in the development of multiple births.

Effect of treatment with acarbose and insulin in patients with non-insulin-dependent diabetes mellitus associated with non-alcoholic liver cirrhosis

AIM

Non-insulin-dependent diabetes mellitus (type 2 diabetes) not responding to dietary treatment alone in patients with non-alcoholic liver cirrhosis is characterized by high postprandial hyperglycaemia. The control of postprandial hyperglycaemia in such patients, is generally achieved by the means of progressively higher doses of insulin, with an increasing risk of hypoglycaemia in the late postprandial period. The aim of this study was to evaluate the use of acarbose for the control of postprandial hyperglycaemia in 100 patients with well-compensated liver cirrhosis and type 2 diabetes treated with insulin.

METHODS

The study was double blind with randomization of treatments into acarbose (52 patients) vs. placebo (48 patients) with parallel branches over a period of 28 weeks.

RESULTS

All patients tolerated the treatments well and no significant variations in liver function tests were observed (< 5% vs. pretreatment). A significant reduction of several parameters was observed only after acarbose treatment: fasting glycaemia (173 +/- 28 vs. 146 +/- 19 mg/dl; p < 0.01), postprandial glycaemia (230 +/- 24 vs. 148 +/- 20 mg/dl; p < 0.01), mean glycaemia (206 +/- 20 vs. 136 +/- 13 mg/dl; p < 0.01), mean variation (180 +/- 14 vs. 51 +/- 10 mg/dl; p < 0.01), HbA1c (8.9 +/- 0.8 vs. 7.2 +/- 0.5; p < 0.05), C-peptide 2 h after a standard meal (4.5 +/- 1.9 vs. 2.8 +/- 1.7 ng/ml; p < 0.05), whereas the parameters did not change significantly after the placebo. After acarbose treatment a significant increase of intestinal voiding/week (+116% vs. +10%; p < 0.01) and a parallel reduction of blood ammonia levels (-52 +/- 9% vs. -9 +/- 5%; P < 0.01) were observed.

CONCLUSIONS

The results clearly document the good tolerability and the absence of toxic effects of acarbose on liver, due to the lack of both intestinal absorption and hepatic metabolism of the drug at doses in the therapeutic range. In fact, acarbose increases the peristalsis movements of the gut, stimulates the proliferation of the saccarolytic bacteria and simultaneously reduces the proliferation of proteolytic bacteria, thus resulting active in the reduction of blood ammonia levels. These effects of acarbose may be advantageously exploited in the treatment of type 2 diabetic patients with well-compensated non-alcholic liver cirrhosis.

Comparative efficacy study of atorvastatin vs simvastatin, pravastatin, lovastatin and placebo in type 2 diabetic patients with hypercholesterolaemia

Although there is little information from primary or secondary prevention trials on cholesterol-lowering medication in diabetic patients, the reduction of elevated cholesterol is widely recommended for this group. The American Diabetes Association (ADA) recommends drug therapy in diabetic patients if low density lipoprotein (LDL)-cholesterol remains at > 130 mg/dl, or > 100 mg/dl in patients with macroangiopathy, after dietary intervention. When cholesterollowering medication is indicated, the choice of the drug must take into account the other lipid abnormalities that are often present and the need to maintain optimal glycaemic control. In the present study we compared the efficacy and safety of the novel HMG-CoA reductase inhibitor atorvastatin at the dose of 10 mg/day with simvastatin , lovastatin and pravastatin at doses of 10, 20 and 20 mg/day, respectively, and placebo, in type 2 diabetic patients with moderate elevation of LDL-cholesterol with or without elevation of triglycerides. All the quoted agents are enzyme inhibitors effective in lowering LDL-cholesterol in humans. The efficacy endpoints were the mean per cent changes in plasma LDL-cholesterol (primary), total cholesterol, triglycerides, and high-density lipoprotein (HDL)-cholesterol concentrations from baseline to the end of treatment (24 weeks). Atorvastatin at a dose of 10 mg/day produced: (1) a significant reduction in LDL-cholesterol (-37%) in comparison with equivalent doses of simvastatin (-26%), pravastatin (-23%), lovastatin (-21%), and placebo (-1%); (2) HDL-cholesterol increases (7.4%) comparable to or greater than those obtained with simvastatin (7.1%), pravastatin (3.2%), lovastatin (7.21%), and placebo (-0.5%); (3) a significantly greater reduction in total cholesterol (- 29%) than that obtained with simvastatin (-21%), pravastain (-16%), lovastatin (-18%), and placebo (1%); and (4) a significantly greater reduction in triglycerides than that obtained with all the other drugs and placebo. In all treatment groups no significant variation in fibrinogen concentration was observed. All reductase inhibitors studied had similar levels of tolerance. There were no incidents of persistent elevations of serum aminotransferases or myositis.

Effects of insulin-glucose infusion on left ventricular function at rest and during dynamic exercise in healthy subjects and noninsulin dependent diabetic patients: a radionuclide ventriculographic study

OBJECTIVES

The aim of this study was to evaluate: 1) the effects of insulin administration on left ventricular ejection fraction (LVEF) during exercise, and 2) the eventual impairment of the cardiovascular response to insulin in noninsulin dependent diabetes mellitus.

BACKGROUND

Insulin influences the cardiovascular system, but its effect on left ventricular function has yet to be established.

METHODS

The effects of normal saline (test A) and insulin-glucose (insulin = 1.7 mU x kg(-1) x min(-1); glucose = 6 mg x kg(-1)min(-1)) (test B) infusions on systolic and diastolic functions at rest and during dynamic exercise were examined by radionuclide ventriculography. Twenty-two noninsulin-dependent diabetic patients and 22 gender, age and body mass index matched healthy subjects were investigated.

RESULTS

Both groups had normal scintigraphic parameters at rest and during dynamic exercise. Rest- and stress-LVEF as well as rest- and stress-peak filling rate were significantly (p < 0.001) lower in diabetic than in healthy subjects, both in test A and B. Rest-LVEF was significantly higher during test B than it was in test A only in diabetic subjects (p < 0.01). Stress-LVEF was significantly higher (p < 0.05) during test B than it was in test A, in both groups. Insulin-glucose infusion did not modify rest- and stress-peak filling rate in either group. No difference in left ventricular end diastolic volume and in mean blood pressure was found between test A and B at rest and during exercise in either group. A significant linear correlation between LVEF and the index of insulin sensitivity was found in diabetic patients.

CONCLUSIONS

In both normal and diabetic humans, insulin induces a very important rise in LVEF after submaximal work. However, the rise is significantly lower in diabetic than in nondiabetic subjects. The increase in exercise-LVEF on insulin is likely due to an enhancement of ventricular contractility. Insulin resistance could justify the lower angioscintigraphic indexes in diabetic subjects.

Predictors of home death in palliative care cancer patients

With recent changes in health care there is greater emphasis on providing care at home, including the support of families to enable more home deaths. Since a home death may not be practical or desirable in every family situation, there is a need for an objective way to assess the viability of a home death in each individual family situation. The purpose of this study was to describe the relative role of predictors of home death in a cohort of palliative care patients with advanced cancer. A questionnaire was created as a means of assessing the viability of a home death. Five questions were included. Ninety questionnaires were administered by home care coordinators. A follow-up questionnaire was administered to record the place of death. Of the 73 evaluable patients, 34 (47%) died at home and 39 (53%) died in hospital or hospice. The desire for a home death by both the patient and the caregiver, support of a family physician, and presence of more than one caregiver were all significantly associated with a home death. Logistic regression identified a desire for home death by both the patient and the caregiver as the main predictive factor for a home death. The presence of more than one caregiver was also predictive of home death. The questionnaire is simple and, if our results are confirmed, it can be used for predicting those who will not have a home death.

Efficacy and safety of acarbose in the treatment of Type 1 diabetes mellitus: a placebo-controlled, double-blind, multicentre study

AIMS

The aim of the study was to evaluate the efficacy and safety of acarbose in patients with Type 1 diabetes mellitus (DM).

METHODS

A multicentre double-blind, randomized, placebo-controlled study was performed. After a 6-week run-in, 121 patients were randomized to acarbose or placebo and to high- or low-fibre diet for 24 weeks. Acarbose dose was 50 mg t.d.s. for the first 2 weeks and 100 mg t.d.s. for the subsequent weeks.

RESULTS

At the end of 24 weeks of treatment the intention to treat analysis showed that acarbose compared with placebo decreased 2 h postprandial plasma glucose levels (12.23 +/- 0.83 vs. 14.93 +/- 0.87 mmol/l; F = 6.1, P < 0.02) (least square means +/- SEM). No significant effect of acarbose was recorded on HbA1c or on the number of hypoglycaemic episodes. The effect of acarbose on blood glucose control was not influenced by the amount of carbohydrate and/or fibre intake. The incidence of adverse events were 75% and 39% in acarbose and placebo groups, respectively; they were mild and confined to the gastrointestinal tract.

CONCLUSIONS

The use of acarbose in combination with insulin reduces postprandial plasma glucose levels in Type 1 diabetic patients who are not satisfactorily controlled with insulin alone but without significant effect on HbA1c.

[Non-insulin-dependent diabetes mellitus associated with nonalcoholic liver cirrhosis: an evaluation of treatment with the intestinal alpha-glucosidase inhibitor acarbose]

Non-insulin-dependent diabetes mellitus not responding to diet only in patients with non-alcoholic liver cirrhosis is characterized by high post-prandial hyperglycemia. The aim of this study was to evaluate the safety and efficacy of 24 weeks of treatment with 300 mg acarbose per day in 76 consecutive outpatients affected by type 2 diabetes and well-compensated liver cirrhosis. The study design was double-blind cross-over vs placebo. All patients tolerated both treatments well, and no significant variations in liver function tests were observed (< 5% vs pre-treatment). A significant reduction of several parameters was observed only after acarbose: fasting glycemia (19 +/- 6 vs 2 +/- 0.5%; p < 0.01), post-prandial glycemia (41 +/- 9 vs 3 +/- 0.6%; p < 0.01), mean glycemia (30 +/- 8 vs 14 +/- 5%; p < 0.01), daily glycemic variation (52 +/- 8 vs 8 +/- 1%; p < 0.01), HbA1c (16 +/- 1 vs 2 +/- 0.5; p < 0.05), incremental area of C-peptide after a standard meal (80 +/- 19 vs 200 +/- 36 ng/mL/300 min; p < 0.01). After acarbose a significant increase of intestinal voiding/week (98 vs 28%; p < 0.01) and a parallel reduction of blood ammonia levels (52 +/- 9 vs 9 +/- 5%; p < 0.01) were observed. Results clearly document the good tolerability and the absence of toxic effects of acarbose on the liver, due to a theoretic absence of both absorption by the gut and hepatic metabolism of the drug. In fact, acarbose increases peristaltic movement of the gut, stimulates the proliferation of saccharolytic bacteria and simultaneously reduces proteolytic bacterial proliferation, thus actively reducing blood ammonia levels. These unexpected effects of acarbose may be used to advantage for the treatment of type 2 diabetes mellitus in patients with well-compensated liver cirrhosis.

The role of autonomic neuropathy as a risk factor of Helicobacter pylori infection in dyspeptic patients with type 2 diabetes mellitus

A high prevalence of upper gastrointestinal symptoms is described in diabetic patients and, at least in part, this has been attributed to abnormal emptying of the stomach. In an unselected small series of dyspeptic patients with Type 2 diabetes mellitus (DM2), we previously described a higher prevalence of Helicobacter pylori (Hp) infection associated with autonomic neuropathy (AN) than in non-diabetic subjects. To evaluate the prevalence of Hp and its relationship with AN, we studied 164 DM2 patients, matched for sex, age ( +/- 5 years) and body weight ( +/- kg) to 164 non-diabetic subjects, all affected with dyspepsia of unknown origin. Results document that the prevalence of peptic ulcer is similar in both groups of patients (20.1 vs 29.3% P = n.s.); chronic gastritis was 50% in the control group and 35.4% in the DN2 group (P < 0.01) and dyspepsia without ulcer and gastritis (simple dyspepsia) was significantly more frequent in DM2 patients than in non-diabetics (44.5 vs 20.7%, P < 0.01). Hp infection was documented by histology of gastrointestinal mucosa in 74.4% of the DM2 patients and in 50% of the controls (P < 0.01) (ulcer: 97 vs 71%, P < 0.05; gastritis: 72 vs 43.5%, P < 0.05; simple dyspepsia: 66 vs 35%, P < 0.01, respectively). Autonomic neuropathy was found in 65.2% of the DM2 patients (90.9% of patients with ulcer, 65.5% with gastritis and 53.4% with simple dyspepsia). A significant concordance (84.7%, P < 0.001) was found between the presence of AN and Hp infection. Data provide, for the first time, direct evidence for a higher frequency of Hp infection in dyspeptic patients affected with DM2 than in non-diabetic subjects. In addition, in diabetic patients the frequency of non-ulcer, non-gastritis dyspepsia is two times higher than in non-diabetics and is strictly associated with autonomic neuropathy, acting as a favoring factor for occurrence and recurrence of gastrointestinal disease.

Soluble CD8 antigen, stimulated C-peptide and islet cell antibodies are predictors of insulin requirement in newly diagnosed patients with unclassifiable diabetes

To evaluate the predictive factors of insulin requirement in newly diagnosed patients with unclassifiable diabetes, 54 consecutive patients, aged less than 35 years, were prospectively followed for 3 years or more. At entry, haemoglobin HbA1c, basal and stimulated C-peptide concentrations, HLA phenotype, islet cell antibodies (ICA) status, and serum levels of soluble CD8 antigen (sCD8) were evaluated. After a median time of 9 (range 2-32) months, 31 patients (group 1) required insulin therapy, whereas 23 patients (group 2) remained non-insulin-requiring after 36 months. Group 1 patients were younger (P < 0.05) and had higher HbA1c and sCD8 serum levels (P < 0.0001), respectively), a higher frequency of ICA positivity and of HLA DR3 and/or DR4 phenotype (P < 0.005 and P < 0.0001, respectively), and lower C-peptide concentrations (P < 0.005 and P < 0.0001, basal and stimulated, respectively) than group 2. The sensitivity, specificity, positive and negative predictive value, and overall accuracy for the subsequent insulin requirement were: sCD8 serum levels (> 737 U/ml), 100%, 65%, 79%, 100% and 85%, respectively; stimulated C-peptide (< 0.60 nmol/l), 71%, 96%, 96%, 74% and 81%, respectively; and ICA positivity (> 20 JDFU), 45%, 91%, 87%, 55% and 65%, respectively. Thus, higher sCD8 serum levels, low stimulated C-peptide concentrations and ICA positivity are the most powerful predictors of subsequent recourse to insulin therapy in young, newly detected patients with unclassifiable diabetes.

Effects of vanadyl sulfate on carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus

The safety and efficacy of vanadyl sulfate (VS) was tested in a single-blind, placebo-controlled study. Eight patients (four men and four women) with non-insulin-dependent diabetes mellitus (NIDDM) received VS (50 mg twice daily orally) for 4 weeks. Six of these patients (four men and two women) continued in the study and were given a placebo for an additional 4 weeks. Euglycemic-hyperinsulinemic clamps were performed before and after the VS and placebo phases. VS was associated with gastrointestinal side effects in six of eight patients during the first week, but was well tolerated after that. VS administration was associated with a 20% decrease in fasting glucose concentration (from 9.3 +/- 1.8 to 7.4 +/- 1.4 mmol/L, P < .05) and a decrease in hepatic glucose output (HGO) during hyperinsulinemia (from 5.0 +/- 1.0 pre-VS to 3.1 +/- 0.9 micromol/kg x min post-VS, P < .02). The improvement in fasting plasma glucose and HGO that occurred during VS treatment was maintained during the placebo phase. VS had no significant effects on rates of total-body glucose uptake, glycogen synthesis, glycolysis, carbohydrate (CHO) oxidation, or lipolysis during euglycemic-hyperinsulinemic clamps. We conclude that VS at the dose used was well tolerated and resulted in modest reductions of fasting plasma glucose and hepatic insulin resistance. However, the safety of larger doses and use of vanadium salts for longer periods remains uncertain.

Left ventricular systolic and diastolic function in severe obesity: a radionuclide study

To verify the impact of sever obesity (defined as body mass index > 31 kg/m2) on left ventricular (LV) function, 32 asymptomatic obese but otherwise healthy subjects (16 men; age 38 +/- 11 years) voluntarily underwent first-pass and equilibrium 99mTc radionuclide angiography at rest and, in 22 of them, during bicycle supine exercise. Data were compared to those obtained from 10 normal volunteers (age 48 +/- 13; p < 0.05, vs. obeses). End-diastolic and stroke volumes did not differ between the two groups, whereas end-systolic volume was significantly higher in obese subjects (67 +/- 20 vs. 49 +/- 20 ml; p < 0.05), and, as a consequence, LV ejection fraction at rest was decreased in obese subjects (59 +/- 7%) compared to normals (65 +/- 6%; p < 0.05). Due to the higher heart rate in obese subjects (81 +/- 13 vs. 69 +/- 10 pbm, respectively; p < 0.05) cardiac output was significantly greater compared to normals (7.1 +/- 0.8 vs. 6.2 +/- 0.2 liters/min, respectively; p < 0.01). During exercise, ejection fraction normally increased in normals (70 +/- 7%; p < 0.001, vs. baseline) but not in obese subjects (60 +/- 9%; p = nonsignificant vs. baseline). In addition, systolic blood pressure/end-systolic volume ratio was significantly decreased in obese subjects (23 +/- 1.3) compared to normals (2.8 +/- 1.6; p < 0.05). Peak filling rate, normalized to end-diastolic counts per second, was significantly lower in obese subjects (2.2 +/- 1.3) compared to normals (2.8 +/- 1.6; P < 0.05). This difference was also true when peak filling rate was computed in stroke counts per second (3.8 +/- 0.8 in obeses vs. 4.4 +/- 0.4 in normals; p < 0.05). Repeat analysis in a subgroup of 10 young obese subjects (age < or = 30 years) confirmed decreased ejection fraction at rest (60 +/- 4%; p < 0.05) and peak filling rate (2.4 +/- 0.4 end-diastolic counts/s; p < 0.05), as well as the lack of ejection fraction increase during exercise (59 +/- 9%). Thus, these data indicate a subclinical impairement of LV systolic and diastolic function at rest and during exercise in asymptomatic severely obese but otherwise healthy subjects.