Quantification of Myocardial Contraction Fraction with Three-Dimensional Automated, Machine-Learning-Based Left-Heart-Chamber Metrics: Diagnostic Utility in Hypertrophic Phenotypes and Normal Ejection Fraction

Aims: The differentiation of left ventricular (LV) hypertrophic phenotypes is challenging in patients with normal ejection fraction (EF). The myocardial contraction fraction (MCF) is a simple dimensionless index useful for specifically identifying cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) when calculated by cardiac magnetic resonance. The purpose of this study was to evaluate the value of MCF measured by three-dimensional automated, machine-learning-based LV chamber metrics (dynamic heart model [DHM]) for the discrimination of different forms of hypertrophic phenotypes. Methods and Results: We analyzed the DHM LV metrics of patients with CA (n = 10), hypertrophic cardiomyopathy (HCM, n = 36), isolated hypertension (IH, n = 87), and 54 healthy controls. MCF was calculated by dividing LV stroke volume by LV myocardial volume. Compared with controls (median 61.95%, interquartile range 55.43-67.79%), mean values for MCF were significantly reduced in HCM-48.55% (43.46-54.86% p < 0.001)-and CA-40.92% (36.68-46.84% p < 0.002)-but not in IH-59.35% (53.22-64.93% p < 0.7). MCF showed a weak correlation with EF in the overall cohort (R2 = 0.136) and the four study subgroups (healthy adults, R2 = 0.039 IH, R2 = 0.089; HCM, R2 = 0.225; CA, R2 = 0.102). ROC analyses showed that MCF could differentiate between healthy adults and HCM (sensitivity 75.9%, specificity 77.8%, AUC 0.814) and between healthy adults and CA (sensitivity 87.0%, specificity 100%, AUC 0.959). The best cut-off values were 55.3% and 52.8%. Conclusions: The easily derived quantification of MCF by DHM can refine our echocardiographic discrimination capacity in patients with hypertrophic phenotype and normal EF. It should be added to the diagnostic workup of these patients.

A Machine Learning Approach for Mortality Prediction in COVID-19 Pneumonia: Development and Evaluation of the Piacenza Score

BACKGROUND

Several models have been developed to predict mortality in patients with COVID-19 pneumonia, but only a few have demonstrated enough discriminatory capacity. Machine learning algorithms represent a novel approach for the data-driven prediction of clinical outcomes with advantages over statistical modeling.

OBJECTIVE

We aimed to develop a machine learning-based score-the Piacenza score-for 30-day mortality prediction in patients with COVID-19 pneumonia.

METHODS

The study comprised 852 patients with COVID-19 pneumonia, admitted to the Guglielmo da Saliceto Hospital in Italy from February to November 2020. Patients' medical history, demographics, and clinical data were collected using an electronic health record. The overall patient data set was randomly split into derivation and test cohorts. The score was obtained through the naïve Bayes classifier and externally validated on 86 patients admitted to Centro Cardiologico Monzino (Italy) in February 2020. Using a forward-search algorithm, 6 features were identified: age, mean corpuscular hemoglobin concentration, PaO2/FiO2 ratio, temperature, previous stroke, and gender. The Brier index was used to evaluate the ability of the machine learning model to stratify and predict the observed outcomes. A user-friendly website was designed and developed to enable fast and easy use of the tool by physicians. Regarding the customization properties of the Piacenza score, we added a tailored version of the algorithm to the website, which enables an optimized computation of the mortality risk score for a patient when some of the variables used by the Piacenza score are not available. In this case, the naïve Bayes classifier is retrained over the same derivation cohort but using a different set of patient characteristics. We also compared the Piacenza score with the 4C score and with a naïve Bayes algorithm with 14 features chosen a priori.

RESULTS

The Piacenza score exhibited an area under the receiver operating characteristic curve (AUC) of 0.78 (95% CI 0.74-0.84, Brier score=0.19) in the internal validation cohort and 0.79 (95% CI 0.68-0.89, Brier score=0.16) in the external validation cohort, showing a comparable accuracy with respect to the 4C score and to the naïve Bayes model with a priori chosen features; this achieved an AUC of 0.78 (95% CI 0.73-0.83, Brier score=0.26) and 0.80 (95% CI 0.75-0.86, Brier score=0.17), respectively.

CONCLUSIONS

Our findings demonstrated that a customizable machine learning-based score with a purely data-driven selection of features is feasible and effective for the prediction of mortality among patients with COVID-19 pneumonia.

4951Long-term prognostic value of adherence to leisure time physical activity prescription in patients undergoing exercise-based cardiac rehabilitation: an inverse dose-response relationship

Background

The benefits associated with leisure time physical activity (LTPA) in primary and secondary cardiovascular prevention has been known for decades. Although several studies demonstrated that exercise-based cardiac rehabilitation (CR) programs reduce mortality, the long-term prognostic value of adherence to LTPA presciption after exercise-based CR has not been well estrablished.

Purpose

Evaluate the long-term prognostic value of adherence to LTPA presciption after exercise-based CR in patients undergoing myocardial revascularization and/or cardiac valve surgery.

Methods

A prospective registry of 2.340 consecutive patients, admitted to the Cardiovascular Prevention and Rehabilitation Unit was created. All patients completed a standard in-hospital CR program. Data regarding LTPA and outcomes were collected. End points were: overall and cardiovascular (CV) mortality and major adverse cardiovascular and cerebrovascular events (MACCEs). The population has been classified into: 1) Physical inactivity: almost completely sedentary or occasional physical activity; 2) Physical activity: regular aerobic LTPA. The amount of LTPA was further collected according to minutes per week.

Results

A total of 1.892 patients with available data on LTPA and outcomes were included in the study; mean follow-up was 50±23 months. One-thousand and twenty-two (54%) patients underwent myocardial revascularization (CABG), 662 (35%) cardiac valve surgery, 208 (11%) combined valve and CABG surgery. Adherence to a regular LTPA was found in the 42% (792 participants) of the population, while 58% (1.100 patients) reported occasional LTPA or a complete physical inactivity. Kaplan-Meier survival curve showed a lower overall mortality (p<0.0001), CV mortality (p<0.0001), and MACCEs (p<0.0001) in LTPA group (figure). After adjustment for age, gender, arterial hypertension, diabetes, type of intervention, glomerular filtration rate and left ventricular ejection fraction, both overall and CV mortality were significantly lower in the LTPA groups (OR=0.24; p<0.0001 and OR=0.35; p<0.046, respectively), as well as combined MACCEs (OR=0.36; p<0.0001). Moreover, an inverse relationship between the increase of minutes per week of LTPA and the decrease of overall (HR 0.990; p<0.0001), CV mortality (HR 0.991; p<0.0001) and MACCEs (HR 0.996; p<0.0001) was found, with 1% reduction of relative risk of events for each minute per week increase of physical activity. Finally, comparing LTPA to standard medical therapy in our population, LTPA showed the lowest number needed to treat (NNT) to save a life (NTT=12).

Central figure

Conclusion

Adherence to leisure time physical activity prescription is independently associated with significant reduction of overall mortality, CV mortality and MACCEs on top of exercise-based CR program after myocardial revascularization and/or cardiac valve surgery.

Acknowledgement/Funding

None

Haemodynamic Correction of Varicose Veins (CHIVA): An Effective Treatment?

Objective:

Evaluation of the feasibility and utility of haemodynamic correction of primary varicose veins (French acronym: CHIVA).

Design:

Prospective, single patient group study.

Setting:

Department of Surgery, University of Ferrara, Italy (teaching hospital).

Patients:

Fifty-five patients with primary varicose veins and a normal deep venous system (ultrasonographic criteria) were studied.

Interventions:

Fifty-five haemodynamic corrections by the CHIVA method described by Franceschi were undertaken. Seven patients were treated for short saphenous vein varices (group A) while 48 patients were treated for long saphenous vein varices (group B).

Main outcome measures:

Clinical: presence of varices and reduction in symptoms. Duplex and continuous-wave Doppler detection of re-entry through the perforators and identification of recurrences or new sites of reflux. Postoperative ambulatory venous pressure and refilling time measurements. Patients were studied for 3 years following surgery.

Results:

In group A, 57% short saphenous vein occlusions with no re-entry through the gastrocnemius and soleal veins were recorded. In group B the long saphenous vein thrombosis rate was 10%. In this group 15% of the patients showed persistence of reflux instead of re-entry at the perforators. Early recurrences were also observed. Overall CHIVA gave excellent results in 78% of the patients. Statistically significant ambulatory venous pressure and refilling time changes were recorded ( p<0.001).

Conclusions:

CHIVA treatment is inadvisable for short saphenous vein varices. Long saphenous vein postoperative thrombosis is related to development of recurrences

Concise Review: Understanding the Renal Progenitor Cell Niche In Vivo to Recapitulate Nephrogenesis In Vitro

Chronic kidney disease (CKD), defined as progressive kidney damage and a reduction of the glomerular filtration rate, can progress to end-stage renal failure (CKD5), in which kidney function is completely lost. CKD5 requires dialysis or kidney transplantation, which is limited by the shortage of donor organs. The incidence of CKD5 is increasing annually in the Western world, stimulating an urgent need for new therapies to repair injured kidneys. Many efforts are directed toward regenerative medicine, in particular using stem cells to replace nephrons lost during progression to CKD5. In the present review, we provide an overview of the native nephrogenic niche, describing the complex signals that allow survival and maintenance of undifferentiated renal stem/progenitor cells and the stimuli that promote differentiation. Recapitulating in vitro what normally happens in vivo will be beneficial to guide amplification and direct differentiation of stem cells toward functional renal cells for nephron regeneration.

SIGNIFICANCE

Kidneys perform a plethora of functions essential for life. When their main effector, the nephron, is irreversibly compromised, the only therapeutic choices available are artificial replacement (dialysis) or renal transplantation. Research focusing on alternative treatments includes the use of stem cells. These are immature cells with the potential to mature into renal cells, which could be used to regenerate the kidney. To achieve this aim, many problems must be overcome, such as where to take these cells from, how to obtain enough cells to deliver to patients, and, finally, how to mature stem cells into the cell types normally present in the kidney. In the present report, these questions are discussed. By knowing the factors directing the proliferation and differentiation of renal stem cells normally present in developing kidney, this knowledge can applied to other types of stem cells in the laboratory and use them in the clinic as therapy for the kidney.

Deletion of NF-κB/p50 influences the outcome of Notch3-dependent T cell leukemia (63.4)

The deregulation of Notch3 signaling inside T-cell compartment of transgenic (N3-tg) mice, induces an aggressive form of T-cell acute lymphoblastic lymphoma (T-ALL), sustained by a constitutive activation of the NF-κB canonical pathway, mainly represented by the p50/p65 heterodimer. To clarify the Notch/NF-κB relationships in the development of T-ALL, we generated double mutant mice, deleted of the NF-κB/p50 subunit in a Notch3 transgenic background (N3-tg/p50-/-). The follow-up of N3-tg/p50-/- versus N3-tg mice revealed that p50 deletion strongly inhibits the development of Notch3-dependent T-ALL. Surprisingly, double mutant succumb earlier than N3-tg mice, displaying the trait of a myeloproliferative disease, with an aberrant accumulation of Mac1+Gr1+ myeloid cells in both spleen and peripheral blood, as well as of granulocyte/monocyte progenitors in the bone marrow. Our preliminary results suggest that Notch3 overexpression in T-cell compartment is able to influence, possibly in trans, the equilibrium of the myeloid compartment and that the ablation of NF-κB canonical pathway may impact on the outcomes of a T-cell specific deregulation of Notch signaling. We provide a useful experimental model to extend our understanding of Notch/NF-κB interplay in hemopoietic system and to unravel novel relationships between lymphoid and myeloid differentiation.

[Epidemiology of tuberculosis in French Brittany: cases notified between 2000 and 2007]

The authors studied the reported cases of tuberculosis diseases in Brittany between 2000 and 2007 via the mandatory notification scheme. One thousand nine hundred and seventy-five cases were notified during the study period. The incidence in French Brittany (eight cases per 100,000) was the third highest in France. A statistically significant negative trend was observed later, mainly attributable to a decrease between 2000 and 2001. The mean patient age at notification was 55 in Brittany versus 46 years of age for the rest of France (p<0.001). Eighty per cent of the patients were born in France versus 46% for the rest of the country. The rate of multiresistance to antibiotics was 1.3% versus 4.6% for the rest of France (p<0.001). The estimated completeness of notification was 80% compared to 70% for the whole country. Despite a decrease of tuberculosis incidence in Brittany, the withdrawal of mandatory vaccination suggests strengthening tuberculosis monitoring in the future.

Follicular dendritic sarcoma within a focus of Castleman's disease. Serial FDG PET/CT in the follow up of recurrence with histopathologic confirmation

We report the case of a 30 year-old man with previous history of melanoma and new diagnoses of localized abdominal Castleman's disease with a focus of follicular dendritic sarcoma within the Castleman's tumor. He presented soon after with a single enlarged abdominal lymph node characterized and followed-up by FDG PET/CT as a low grade malignancy consistent with Castleman's recurrence. However, other imaging techniques raised the possibility of sarcoma/ melanoma recurrence. Final surgical resection allowed histological confirmation of the FDG PET/CT findings. To our knowledge, this is one of the few cases in the literature of Castleman's disease and follicular dendritic sarcoma association in the same focus. This is the first paper to our knowledge to use FDG PET/CT as the follow-up imaging tool for serial characterization of recurrence of Castleman's disease and follicular dendritic sarcoma. FDG PET/CT may be useful in the differentiation between Castleman's disease and malignancies associated with this disease.

Diagnosis of aseptic deep venous thrombosis of the upper extremity in a cancer patient using fluorine-18 fluorodeoxyglucose positron emission tomography/ computerized tomography (FDG PET/CT)

We describe a patient with a history of recurrent squamous cell carcinoma of the tongue and abnormal FDG uptake in the left arm during a re-staging FDG PET/CT. After revision of the patient's clinical history, tests and physical exam, the abnormal FDG uptake was found to correspond to an extensive aseptic deep venous thrombosis of the upper extremity.

Imaging cell death in vivo

A technique to image programmed cell death would be useful both in clinical care and in drug development. The most widely studied agent for the in vivo study of apoptosis is radiolabeled annexin V, an endogenous protein labeled with technectium-99m, now undergoing clinical trials in both Europe and the United States. While annexin V has been studied extensively in humans the precise mechanism(s) of uptake this agent in vivo is unclear and needs further study. Other agents are also under development, including radiolabeled forms of Z-VAD.fmk, a potent inhibitor of the enzymatic cascade intimately associated with apoptosis. In addition other technologies, such as diffusion weighted magnetic resonance imaging and magnetic resonance imaging with contrast agents, such as small paramagnetic iron oxide particles coated with peptides have also been advocated as methods to monitor apoptotic cell death. The potential applications of imaging apoptosis as a marker of early response to therapy in cancer, acute cerebral and myocardial ischemic injury and infarction, immune mediated inflammatory disease and transplant rejection are reviewed.

Evaluation of renal graft haemodynamia by 51Cr-EDTA and o-[131I]iodohippurate: its use in the early diagnosis of glomerular hyperfiltration

Chronic rejection is the most important cause of renal graft dysfunction. Non-immunological mechanisms have been suggested as a probable origin of chronic graft rejection, provoking a decrease in renal mass function, followed by glomerular hyperfiltration in the remnant nephrons, which could cause progressive glomerulosclerosis and functional loss. Early, or preclinical, identification of patients with glomerular hyperfiltration, defined as an increase in glomerular filtration fraction (GFF) and in glomerular capillary pressure (GCP), could prolong graft life. The objective of this study was to evaluate, non-invasively, stable renal graft haemodynamia and early glomerular hyperfiltration. We studied 116 renal transplant patients with stable renal function and five healthy living kidney donors with normal renal function. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined using 51Cr-EDTA and o-[131I]iodohippurate, respectively. GFF was obtained from the relation between GFR and ERPF, and GCP from a mathematical model (Hall-Gomez' formula). A simultaneous analysis of renal function was performed. In transplant patients, the GFR and ERPF were significantly lower than in healthy, living, kidney donors (P<0.02). The same trend was observed for GCP (P<0.01), while GFF was not significantly different. Twelve patients (10.3%) had criteria of glomerular hyperfiltration. In patients without criteria of glomerular hyperfiltration, plasma level and clearance of creatinine were 128+/-33 micromol.l-1 and 56+/-15 ml.min-1, respectively; and in those patients with glomerular hyperfiltration criteria were 108+/-18 micromol.l-1 (P=NS) and 83+/-24 ml.min-1 (P=0.002) respectively. It is concluded that determinations of GFR, ERPF, GFF and GCP allow non-invasive evaluation of renal graft haemodynamia and can be useful in the early detection of glomerular hyperfiltration.

Temperature measurement in intensive care patients: comparison of urinary bladder, oesophageal, rectal, axillary, and inguinal methods versus pulmonary artery core method

OBJECTIVE

Comparisons of urinary bladder, oesophageal, rectal, axillary, and inguinal temperatures versus pulmonary artery temperature.

DESIGN

Prospective cohort study.

SETTING

Intensive Care Unit of a University-Hospital.

PATIENTS

Forty-two intensive care patients requiring a pulmonary artery catheter (PAC).

INTERVENTION

Patients requiring PAC and without oesophageal, urinary bladder, and/or rectal disease or recent surgery were included in the study. Temperature was simultaneously monitored with PAC, urinary, oesophageal, and rectal electronic thermometers and with axillary and inguinal gallium-in-glass thermometers. Comparisons used a Bland and Altman method.

MEASUREMENTS AND MAIN RESULTS

The pulmonary arterial temperature ranged from 33.7 degrees C to 40.2 degrees C. Urinary bladder temperature was assessed in the last 22 patients. A total of 529 temperature measurement comparisons were carried out (252 comparisons of esophageal, rectal, inguinal, axillary, and pulmonary artery temperature measurements in the first 20 patients, and 277 comparisons with overall methods in the last patients). Nine to 18 temperature measurement comparisons were carried out per patient (median = 13). The mean differences between pulmonary artery temperatures and those of the different methods studied were: oesophageal (0.11+/-0.30 degrees C), rectal (-0.07+/-0.40 degrees C), axillary (0.27+/-0.45 degrees C), inguinal (0.17+/-0.48 degrees C), urinary bladder (-0.21+/-0.20 degrees C).

CONCLUSION

In critically ill patients, urinary bladder and oesophageal electronic thermometers are more reliable than the electronic rectal thermometer which is better than inguinal and axillary gallium-in-glass thermometers to measure core temperature.

Effect of Sildenafil on hypertensive lower oesophageal sphincter

BACKGROUND

Sildenafil relaxes the muscle cells of the penis arterioles by inhibiting phosphodiesterase-type 5 (PD-5), inactivating the nitric oxide-stimulated cyclic guanosine monophosphate. We investigated whether this effect of Sildenafil is also displayed on the muscles of the hypertensive lower oesophageal sphincter (LES).

METHODS

In 14 patients with symptomatic hypertensive LES, oesophageal motility was recorded by means of a low-compliance manometric system with five manometric ports for the oesophageal body and a sleeve for the sphincter. After a basal period of 60 min a tablet of Sildenafil 50 mg (group A; seven patients) or one of placebo (group B; seven patients) ground and dissolved in 20 cc of water was infused in the stomach, randomly and in double-blind manner. Recording continued for a further 60 min. Sphincter tone and pressure wave amplitude were measured each minute and the values averaged for each 5-min period for the post-infusion period of 60 min. The values of the whole post infusion period, the lowest values among the 5-min periods (nadir values) and the values of the last 5-min periods were compared with the basal values in each group, and those of group A were compared with the corresponding values of group B.

RESULTS

Sphincter tone and wave amplitude showed after Sildenafil a significant decrease comparable that of the basal period and the placebo. The inhibitory effect reached its maximum 10 min after the infusion and lasted approximately 1 h.

CONCLUSIONS

Sildenafil inhibits the lower oesophageal sphincter tone and pressure wave amplitude of patients with symptomatic hypertensive LES. These findings suggest a clinical application of PD-5 inhibitors in the treatment of spastic oesophageal motor disorders.

Detection and characterization of hibernating myocardium

Since Tennant and Wiggers observed that coronary occlusion caused a reduction in cardiac contractile function, a lot has been written about the concept of hibernating myocardium. Known as the 'smart heart', hibernating myocardium is characterized by a persistent ventricular myocardial dysfunction with preserved viability, which improves with the relief of the ischaemia; this chronic downregulation in contractile function being a protective mechanism to reduce oxygen demand and thus ensure myocyte survival. This improvement usually results in an enrichment in the quality of life as well as enhanced ventricular function. In fact, it has been observed that the cardiac event rate in patients with viable dysfunctional left ventricular segments who are medically treated, is higher than the event rate in patients with comparable viability who are revascularized. Different degrees of histological alteration have been seen in hibernating myocardium, ranging from cellular de-differentiation (fetal phenotype) to cellular degeneration. Cellular de-differentiation has been associated with repetitive stunning. On the other hand, cellular degeneration (with more extensive fibrosis) has been associated with chronic low myocardial blood flow and a longer time to recovery after revascularization. These histological patterns may suggest an evolution from cellular de-differentiation to degeneration, which ends in scar formation if no revascularization is performed. In fact, several studies have described the clinical value of identifying and revascularizing hibernating segments as early as possible, to minimize fibrosis and morbidity from adverse events. Detection of hibernating myocardium still remains an important clinical problem. Imaging modalities to assess myocardial viability must differentiate potentially functional tissue from myocardium with no potential for functional recovery. These techniques fall into three broad categories: ventricular function assessment, myocardial perfusion imaging and myocardial metabolic imaging. PET imaging with fluorine-18 fluorodeoxyglucose (18F-FDG) and 11C-acetate, single photon emission computed tomography (SPECT) with thallium and 99mTc-sestamibi, dobutamine echocardiograpy, magnetic resonance imaging (MRI) and fast computed tomography (CT) have been used for this purpose. PET imaging, in both perfusion and glucose metabolic activity, has become a standard for myocardial viability assessment, however, similar information may be available from carefully performed studies with perfusion tracers alone.

Effects of sildenafil on esophageal motility of normal subjects

Sildenafil shows an intense and prolonged inhibitory effect on the smooth muscle cells of corpus cavernosum arterioles by blocking phosphodiesterase type 5 that inactivates the nitric oxide-stimulated cyclic guanosine monophosphate. We investigated if this inhibitory effect is also displayed on smooth muscle cells of the esophagus. In 16 normal subjects (9 men and 7 women, mean age 34 years, range 22-56) esophageal motility was recorded by means of a low-compliance manometric system with side holes for the esophageal body and a sleeve for the lower esophageal sphincter (LES). After a basal period of 60 min, a tablet of sildenafil 50-mg ground and dissolved in water was infused in the stomach in eight subjects (group A) and a placebo tablet in the other eight subjects (group B), randomly and in a double-blind manner; the recording continued for another 60 min. LES tone and postdeglutitive residual pressure, as well as amplitude, propagation velocity, and onset latency of contractions were measured each minute, the values averaged every 5 min, and the mean of the entire basal and postinfusion periods was calculated. The postinfusion values were compared with the basal values in each group and with the corresponding values of the other groups. The percent variations of postinfusion values with respect to basal values were also compared. Sildenafil induced a statistically significant decrease of LES tone, residual pressure, wave amplitude, and propagation velocity and a significant increase of onset latency of pressure waves in comparison with the values of the basal period and placebo. The inhibitory effect reached its maximum 10-15 min after the infusion and lasted about 1 hr. In conclusion, sildenafil markedly inhibits the motor activity of the esophageal musculature by decreasing LES pressure, wave amplitude, and propagation velocity and increasing the onset latency of pressure waves.

Sildenafil inhibits gastroduodenal motility

BACKGROUND

Sildenafil shows an intense and prolonged inhibitory effect on the smooth muscle cells of corpus cavernosum arterioles by blocking phosphodiesterase-type 5, which inactivates the nitric oxide-stimulated cyclic guanosine monophosphate.

AIM

To investigate whether this inhibitory effect is also displayed on the musculature of the gastroduodenal tract.

METHODS

In 16 normal subjects, antroduodenal motility was recorded by means of a low-compliance manometric system. Ten minutes after the appearance of a phase III of the migrating motor complex, a tablet of sildenafil 50 mg, dissolved in 20 mL of water, was infused in the gut of eight patients, or a placebo in the other eight patients, randomly and in a double-blind manner, continuing the recording for 90 min. The frequency and amplitude of antral and duodenal waves, measured during the first 60 min after infusion in the two groups, were compared statistically. In addition, the duration of antral and duodenal phases I, and the number of phases III occurring during the whole 90 min after infusion, were compared in the two groups.

RESULTS

Antral and duodenal wave frequency and amplitude were significantly lower during the first 60 min after sildenafil administration. Both antral and duodenal phases I were significantly longer after sildenafil than after placebo, and the number of phases III which occurred during the 90 min after sildenafil was significantly lower than after placebo.

CONCLUSIONS

Sildenafil inhibits interdigestive motor activity of the antrum and duodenum.

Effect of a mineral water on gastric emptying of patients with idiopathic dyspepsia

The antidyspeptic property of mineral waters has for many years been based on empirical data. In the present paper we evaluated the effects of one type of mineral water, Tettuccio water from Montecatini, on gastric emptying in patients with idiopathic dyspepsia. Fourteen subjects, eight patients with idiopathic dyspepsia and delayed gastric emptying at scintigraphy and six healthy subjects with normal gastric emptying were studied. The gastric emptying of mineral water was studied with a scintigraphic method and compared with that of tap water. In patients with idiopathic dyspepsia, gastric emptying of both waters was slower than in controls but the gastric emptying of mineral water was significantly faster than that of tap water, both in dyspeptic patients and in healthy subjects. In conclusion, this mineral water stimulates gastric emptying. Further studies are needed on the possible role of this water in the management of chronic idiopathic dyspepsia.

Influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation in ischaemic heart disease

Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracers was quantified and expressed as a percentage of maximum peak activity. The percentage < or =55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%+/-1.4% vs 1.4%+/-1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial perfusion, but does not cause changes in sympathetic myocardial innervation.

Effects of sildenafil on esophageal motility of patients with idiopathic achalasia

BACKGROUND & AIMS

Sildenafil shows an intense and prolonged inhibitory effect on the smooth muscle cells of the human corpus cavernosum by blocking phosphodiesterase type 5 that destroys nitric oxide-stimulated cyclic guanosine monophosphate. We investigated if sildenafil possesses a similar effect on the esophageal musculature of patients with achalasia, where there is an impairment of nitric oxide production similar to that of functional impotence.

METHODS

In 14 patients affected by achalasia with an esophageal diameter of </=5 cm, esophageal motility was recorded with a low-compliance manometric system. After a basal period of 30 minutes, a 50-mg tablet of sildenafil dissolved in water was infused in the stomach in 7 patients and one of placebo in the other 7 patients, randomly and in double-blind manner, continuing the recording for 60 minutes.

RESULTS

Lower esophageal sphincter tone, residual pressure, and wave amplitude after sildenafil showed a significant decrease compared with both the basal period and the placebo group, with a marked interpatient variability. The inhibitory effect reached its maximum (about -50%) 15-20 minutes after the infusion and lasted <1 hour. Propagation of pressure waves was not modified by sildenafil.

CONCLUSIONS

Sildenafil inhibits the contractile activity of the esophageal musculature of patients with achalasia, decreasing lower esophageal sphincter tone and residual pressure as well as contraction amplitude.

Dose-related stimulatory effect of clarithromycin on interdigestive gastroduodenal motility

BACKGROUND/AIMS

The effect on interdigestive gastroduodenal motility of different doses of clarithromycin, an antibiotic commonly used for Helicobacter pylori eradication, has been investigated.

METHODS

Gastroduodenal motility was recorded by means of a low-compliance manometric system in 15 healthy subjects. Thirty minutes after the first phase III of the migrating motor complex, clarithromycin (CLA) was infused intravenously at a dose of 100 mg in 5, 250 mg in 5 and 400 mg in 5 subjects, randomly and in a double-blind manner, continuing the recording for at least 1 h. A further study was carried out on 10 subjects, 5 of whom received 50 mg CLA and 5 normal saline with the same modalities.

RESULTS

After 100 mg CLA a premature gastroduodenal phase III ensued in all cases, which showed a duration, propagation velocity and wave frequency not significantly different from the spontaneous one and was followed by a clear phase I. A premature gastroduodenal phase-III-like activity occurred in 3 cases of 250 mg CLA and 2 cases after 400 mg CLA, followed by a very short or absent phase I and characterized by a long duration of the antral phase III, while in the remaining cases a long-lasting sequence of about 1/min of antral waves propagated to the duodenum appeared, sometimes preceded by an antral phase-III-like activity not propagated to the duodenum. After 50 mg CLA a premature phase III appeared in 2 cases, while a not premature phase III appeared in 2 cases after saline.

CONCLUSION

CLA shows a dose-related stimulatory effect on interdigestive gastroduodenal motility varying from the initiation of a typical phase III to a prolonged sequence of gastroduodenal coordinated waves. These motor effects of CLA suggest potential therapeutic applications.

Effect of intravenous clarithromycin on interdigestive gastroduodenal motility of patients with functional dyspepsia and Helicobacter pylori gastritis

Gastroduodenal motility of 16 patients complaining of functional dyspepsia and Helicobacter pylori gastritis was recorded by means of a low-compliance manometric system with four recording ports in the stomach and four in the duodenum. Clarithromycin (CLA) 250 mg (group A: 8 patients) or normal saline solution (group B: 8 patients) was infused intravenously randomly and in double-blind manner 30 min after the end of the first recorded activity front (AF) of the migrating motor complex or, in the absence of AFs, after 200 min of recording, continuing the recording until an AF was observed during the subsequent 200 min. CLA administration was followed by a typical gastroduodenal AF in a significantly higher number of patients than saline administration. In addition, the time-lag between the drug administration and the appearance of AFs was 22 min +/-7.4 (mean +/- SD), significantly shorter than after saline (109+/-56 min) and the CLA-related duodenal AFs showed a duration of 7.4 min +/-1.6 in group A, significantly longer than that of the spontaneous AFs (3.5 min +/-1), while in group B AF duration after saline was not significantly different from that of the spontaneous ones. In conclusion, clarithromycin is able to stimulate cyclic interdigestive gastroduodenal motility. This prokinetic property of clarithromycin is not unexpected because it is a macrolide like erythromycin, the prokinetic activity of which is well known, and could be utilized for therapeutic uses.

[Changes caused by mineral water on gastrointestinal motility in patients with chronic idiopathic dyspepsia]

BACKGROUND

The antidyspeptic property of mineral waters has been based for ages on empirical data. In the present paper the effects of one of them (Tettuccio, Montecatini) on gastrointestinal motility of patients with dyspepsia has been evaluated.

METHODS

The study was carried out on 24 patients with idiopathic dyspepsia and delayed gastric emptying at scintigraphy and 18 healthy subjects with normal gastric emptying. The gastric emptying of this mineral water was studied with a scintigraphic method in comparison with tap water, while its effects on gastroduodenal contractions were evaluated by of manometry.

RESULTS

The gastric emptying of this mineral water was significantly faster than that of tap water, both in dyspeptic patients and in normals. Manometric examination showed that the administration of mineral water induced a brief decrease of phasic motor activity, followed by a progressive increase, which in some cases ended in an activity front of the Migrating Motor Complex.

CONCLUSIONS

This mineral water has a stimulating effect on both gastric emptying and interdigestive cyclic motor activity of the gastroduodenal tract. Both these effects could be useful in the treatment of chronic idiopathic dyspepsia and impaired gut clearing.

[Anti-pseudomonas-specific precipitins as a marker of chronic infection in patients with cystic fibrosis]

AIMS

The authors underline the characteristics of Pseudomonas aeruginosa and its methods of action on bronchial mucosa in cystic fibrosis. They then discuss the two concepts of "colonisation" and "chronic infection".

METHODS

The level of "infection" was evaluated using an immunoelectrophoretic method involving the precipitation of bands of specific precipitins. A technical description of the method is included. The authors illustrate the use of the method in 78 cases of cystic fibrosis, comparing the positive results obtained using precipitin electrophoresis with the results of direct bacteriological findings.

RESULTS

Using the bacteriological criteria, a total of 26.9% of patients were diagnosed as infected, whereas this percentage rose to 32.1% using precipitins. 87.2% of cases were concordant using both methods.

CONCLUSIONS

As a practical solution, the authors recommend that the two methods are combined, thus obtaining a marked reduction in the number of false positives with obvious consequences in terms of therapeutic decisions.

Effect of omeprazole on interdigestive gastroduodenal motility of patients with ulcer-like dyspepsia

BACKGROUND/AIMS

As omeprazole, an antisecretory drug, is largely used in the treatment of acid-related diseases, we investigated its effects on the interdigestive gastroduodenal motility of ulcer-like dyspepsia.

METHODOLOGY

Gastroduodenal motility was recorded manometrically in 9 patients complaining of ulcer-like dyspepsia with normal gastric emptying at scintigraphy, without ulcerative lesions and H. pylori infection at endoscopy, and without diseases known to affect gut motility (group ULD), and in a group of 9 healthy subjects as control (group C). After a period sufficient to record two consecutive phases III of the migrating motor complex (MMC) in patients of group ULD, omeprazole 20 mg was infused intravenously 30 min after the end of the last duodenal phase III and the recording was continued to the next one.

RESULTS

With respect to the control group, the group ULD showed a significantly longer MMC cycle duration, a frequent absence of gastric phases III and a shorter duration of duodenal phases III. Omeprazole administration in group ULD was followed after 18.9 +/- 8.5 min by a typical gastroduodenal phase III and, consequently, the duration of the omeprazole-related cycle was significantly shortened. These omeprazole-related phases III started from the stomach in nearly all cases and showed a significantly longer duration at the duodenal level with respect to the spontaneous ones.

CONCLUSIONS

Patients with ulcer-like dyspepsia showed a decrease in frequency and duration of gastroduodenal phases III. The omeprazole intravenous administration induced the anticipated appearance of an apparently normal gastroduodenal phase III, probably by suppressing the inhibitory action of acid secretion.

Effects of oral clarithromycin and amoxycillin on interdigestive gastrointestinal motility of patients with functional dyspepsia and Helicobacter pylori gastritis

BACKGROUND

Clarithromycin and amoxycillin are antibiotics commonly used in association for Helicobacter pylori eradication. Because this treatment, which lasts 1-2 weeks, is frequently associated with gastrointestinal symptoms, we investigated the effects of these antibiotics on gastrointestinal motility.

PATIENTS AND METHODS

Gastroduodenal motility was recorded in 14 patients with functional dyspepsia and H. pylori gastritis by means of a low-compliance manometric system with four recording ports in the stomach and four in the duodenum. Two tablets of clarithromycin 250 mg (seven patients, clarithromycin group) or one of amoxycillin 1 g (seven patients, amoxycillin group), ground and dissolved in 20 mL of water, were given randomly and in double-blind manner 30 min after the end of the first activity front (AF) of the migrating motor complex (MMC) or, in the absence of AFs, after at least 200 min of recording. Recording continued until an AF was observed during the subsequent 200 min.

RESULTS

Clarithromycin administration was followed by a typical gastroduodenal AF in a significantly higher number of patients than for amoxycillin administration. In addition, the time lag between clarithromycin administration and the appearance of AFs was 48 min +/- 8.5 (mean +/- s.d.), significantly shorter than after amoxycillin (121 min +/- 29). The clarithromycin-related duodenal AFs showed a duration of 6.6 min +/- 1.5, significantly longer than that of the spontaneous AFs (3.6 min +/- 1.2, P < 0.01), while the amoxycillin-related AFs were not significantly different from the spontaneous ones.

CONCLUSION

Clarithromycin stimulated cyclic gastroduodenal motility, while amoxycillin was ineffective. It is likely that symptoms during the eradication treatment are due to this effect of clarithromycin.

Complete identification of cystic fibrosis transmembrane conductance regulator mutations in the CF population of Saguenay Lac-Saint-Jean (Quebec, Canada)

Over the past few years, we have conducted a systematic study of 230 cystic fibrosis (CF) chromosomes in the Saguenay Lac-Saint-Jean (SLSJ) population which has a high CF incidence (1/936 live births). We identified 11 mutations accounting for 100% of the CF chromosomes found in patients born in SLSJ. Our results indicate that denaturing gradient gel electrophoresis (DGGE) is a powerful method of identifying CF mutations. They have also considerable implications for genetic counselling and molecular characterization of doubtful patients. They make carrier screening technically feasible in this population.

A study of the dielectric properties of E. coli ribosomal RNA and proteins in solution

The permittivity of ribosomal proteins and ribosomal RNA (rRNA) in solution was measured in the range 100 kHz to 1 GHz at four different temperatures (5, 15, 25 and 35 degrees C). The experimental dielectric relaxation was analysed by the Cole-Cole equation and, from the best-fit parameters, the average values of the dipole moment and molecular radius of the proteins were obtained. The activation enthalpy was calculated from an Arrhenius plot of the relaxation time. The energy involved in the dielectric polarization of free proteins has a magnitude of about one hydrogen bond. The data on RNA were analysed according to the Mandel model. This analysis allowed the calculation of the "subunit b" as defined by Mandel. This parameter is dependent on the temperature and therefore the relaxation time does not follow the Arrhenius law. Our data thus show that, in solution, the rRNA structure is thermally rather unstable and highly flexible.

Membranous obstruction of the inferior vena cava and Budd-Chiari syndrome. Report of a case

Membranous obstruction of the inferior vena cava (MOIVC) is a rare, congenital or acquired, cause of Budd-Chiari syndrome leading to hepatocellular carcinoma in 20 to 40% of the patients. It has a very poor prognosis when treated medically and balloon angioplasty (PTA) represents, nowadays, the treatment of choice, having no mortality or significant morbidity with follow-up as long as 5 years; transatrial membranotomy, direct reconstruction of IVC and bypass surgery are alternative techniques when PTA is not feasible. One case of Budd-Chiari syndrome due to an incomplete membranous obstruction of the suprahepatic portion of the inferior vena cava is reported. A PTA was not feasible as it was not possible to pierce the membranous obstruction. A successful inferior vena cava-right atrium PTFE bypass, with a 3.5-year follow-up, was performed. This surgical approach is a valuable alternative to transatrial membranotomy and direct reconstruction of the IVC.

[Hernia surgery with short hospitalization]

The hospital stay of 55 patients, 47 males and 8 females, admitted to hospital for surgical repair of inguinal (53 procedures) and crural (4 procedures) hernias was analyzed. The mean age was 60.7 years (range from 25 to 82 years), local anesthesia was the method of choice (55 procedures), it has suppressed post-anesthetic respiratory and urinary troubles. The mean hospital stay was 1.18 days. One superficial skin hematoma and 1 wound infection were found, local anesthetic intolerance occurred in 1 case, and low fever in three cases. Over 90 percent of patients were favourable to short stay surgery for hernia repair at 30 days follow-up. The authors conclude on the feasibility, acceptability, social benefits and usefulness of short stay and day care surgery for hernia repair.

[Pseudomonas aeruginosa colonization in Turin CF center. Microbiological and therapeutic observations]

We reviewed 4,277 sputum cultures performed in our FC patients during antipseudomonas courses of antibiotic therapy. The median age of colonization is 8.6 years, and the chronically infected subjects are 33.65% of all our patients. The most efficient antibiotics were imipenem, aztreonam, ceftazidime and amikacin. Ceftazidime gave the best results in terms of antibiotic resistance.

[Clinical and hemodynamic effects of external valvuloplasty of the sapheno-femoral junction]

Selected patients with primary varicose vein disease and sapheno-femoral reflux as the only point of regurgitation in the affected lower limb and duplex evidence of mobile valve leaflets underwent external valvuloplasty of the sapheno-femoral junction. Operations were performed under local anesthesia in one day-surgery. One PTFE sleeve 0.4 mm thick, in average 1.2 cm long and able to uncircle a circumference in average of 1.7 cm was put around the terminal Long Saphenous vein valve, located in the last centimeter of this vein. If also the subterminal Long Saphenous Vein valve site, located 5 cm below is dilated a second valvuloplasty was performed. In 15 case we used intra-operatory video-angioscopy guide. This examination allowed us to exclude two patients with valve damages not duplex demonstrable. Furthermore angioscopy permitted immediate demonstration of restored valvular function. Follow-up lasted on average 48 months: two early postoperative long saphenous vein thrombosis, and two late sapheno-femoral reflux recurrences were the main complications. We never observed graft infection. AVP was reduced and RT, measured by the means of LRR, had a prolongation after surgery. Both measurements had an highly significant difference from a statistical point of view, comparing pre and postoperative values. 95% of the operated patients have stable varices reduction. Long Saphenous Vein patency was recorded in 37 cases (92.5%). On the contrary, after high ligation, the fate of the saphenous vein in 21% of case is the occlusion. Symptoms of venous insufficiency disappeared completely in 80% of cases and improved in 95% of the operated patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Video-assisted venous surgery]

The use of intraoperative angioscopy, till now utilized exclusively in arterial surgery, is now used also in venous surgery. From January 1992 54 patients underwent to video-guided venous surgery: 23 cases of external valvuloplasty of the sapheno-femoral junction (EV-SFJ), 25 cases of hemodynamic correction of varicose veins (French acronyms CHIVA), 5 cases of high ligation plus long saphenous vein intraoperative sclerotherapy (HL-IS) 1 case of sub-fascial perforators interruption (SPI), the only extraluminal videoguided procedure. We have used 3 different video-angioscopes: a 1 mm monofibroscopy let in a 6 Fr Fogarty catheter, a disposable 2,8 mm colangioscope and a 2,2 mm operative angioscope. For the perforators interruption we have utilised the thoracoscope. EV-SFJ: the angioscopy has confirmed the presence of normal valvular cusps in a dilated vein wall in 21 cases, so excluding 2 patients from the planned treatment. At the end of the operation the angioscope has verified the reapproach of valvular cusps. CHIVA: the angioscopy has allowed to identify the exact points of the superficial venous system which should be interrupted, according to the Franceschi's theory. This procedure can avoid the technical errors due to intraoperatory misleadings of the duplex mapping. HL-IS: consists of a classic high ligation followed by long saphenous vein intraoperative sclerotherapy. The angioscopy has allowed a complete deconnection of the long saphenous vein from tributaries and perforators. Furthermore has facilitate the proportional distribution of the sclerosing agent along the long saphenous vein. SPI: the videoassistance have permitted the identification of the insufficient perforating veins reducing their surgical exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

[Video-laparoscopic splenectomy: experience in 3 cases]

BACKGROUND

In selected cases the spleen can be removed:

METHODS

2 women and 1 men with immune thrombocytopenic purpura, with hypersplenism without splenomegaly, underwent splenectomy by laparoscopic means.

RESULTS

In 2 cases the splenectomy has been performed entirely by laparoscopic means. In 1 case the operation has been converted as we have not been able to control a venous bleeding from injured hilar spleen vessels.

DISCUSSION

No particular technical problems arose in the 2 cases entirely conducted by laparoscopic means. Care must be taken manipulating the hilar vessels as the veins are fragile and their bleeding is difficult to be controlled in laparoscopy. The laparoscopic splenectomy seems to offer less postoperative pain, shorter hospitalization and improved cosmesis according to our previous experience with open splenectomy.

CONCLUSIONS

The good result of the operations encourages the laparoscopic approach to splenectomy, in selected cases.

[Esophageal anastomosis using a stapler: new technical variants]

Stapling techniques are considered the safer alternative for esophageal anastomosis in the Authors experience. In order to further improve results they suggest stapled esophageal anastomoses should be constructed avoiding purse-string sutures and the use of purse-string devices or Satinsky forceps.