Teaching Control during the COVID-19 Pandemic.

This paper aims to analyze some different solutions that were adopted in control education activities during the pandemic. The authors of this paper are educators in the control education field from different countries on all the continents, who have developed a questionnaire with the idea of collecting data about the COVID-19 pandemic impact on the control education activities. The main objective is to study the diverse alternatives that were used worldwide to perform the online educational activities during that period, such as methodologies, tools, learning management systems (LMS), theoretical exercises, laboratory experiments, types of exams, simulators, software for online lecturing, etc. As a result, comparisons between pre-and during-pandemic educational resources and methods are performed, where useful ideas and discussions are given for the control education community.

The novel Mechanical Ventilator Milano for the COVID-19 pandemic.

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Application of SSOD-PI and PI-SSOD event-based controllers to greenhouse climatic control.

In this work, an application of the Symmetric Send-On-Delta (SSOD) event-based controllers to the inside air temperature control of the greenhouse production process is presented. The control technique analysis is split into two stages. The first stage is devoted to determine the proper controller parameters and to check the influence of the Send-On-Delta (SOD) threshold value through simulation study. At the second stage, experimental tests on the real greenhouse facilities are performed. The obtained results show that the analyzed control techniques handle the control task with desired accuracy and performance. In particular, the proposed control system saves costs related with energy consumption and wear minimization, by achieving a satisfactory performance at the same time.

Similarities and differences in the antihypertensive effect of two calcium antagonist drugs, verapamil and nifedipine.

The short- and long-term effects of two calcium channel blocking drugs, verapamil and nifedipine, on blood pressure, heart rate, plasma catecholamines, plasma renin activity, plasma volume and cardiac performance (echocardiography) were studied in essential hypertensive patients and in normal subjects. Verapamil, 160 mg orally, reduced blood pressure within 60 minutes in 22 hypertensive patients, but not in 12 normotensive subjects. Nifedipine, 10 mg sublingually, reduced blood pressure within 15 minutes in 19 hypertensive patients, but not in 7 normotensive subjects. Plasma noradrenaline was significantly increased both in normal subjects and in hypertensive patients only after nifedipine was administered. Verapamil (80 mg three times a day) first, and nifedipine (10 mg three times a day) thereafter, or vice versa, were given to 12 hospitalized hypertensive patients on a fixed sodium and potassium intake; the drugs produced similar blood pressure reductions, but heart rate and plasma catecholamines were increased only after nifedipine (p less than 0.05). Neither drug affected plasma volume, aldosterone or plasma renin activity. Long-term ambulatory treatment with verapamil (80 or 160 mg three times a day for 2 to 4 months) or nifedipine (10 mg three times a day for 2 months) produced changes in all variables that were similar to those observed in the hospital (controlled) study. Shortening fraction was significantly increased after nifedipine (p less than 0.05) but no change was observed after verapamil. In conclusion, blood pressure is effectively reduced by both verapamil and nifedipine; an appreciable adrenergic stimulation may be caused by nifedipine, but usually not by verapamil, and fluid retention, renin release or myocardial depression is not observed during verapamil or nifedipine treatment.

Angiotensin II type 1 receptor A/C1166 polymorphism. Relationships with blood pressure and cardiovascular structure.

The angiotensin II type 1 (AT1) receptor has a key role in mediating the vasoconstrictor and growth-promoting effects of angiotensin II. It has been reported that a polymorphism of the AT1 receptor gene (an A/C transversion at position 1166) may be associated with cardiovascular phenotypes, such as arterial blood pressure and aortic stiffness, that underlie a condition of increased cardiovascular risk. We examined a sample of 212 subjects randomly selected from a general population in northern Italy to investigate the role of AT1 receptor gene polymorphism, in the regulation of blood pressure and cardiovascular growth. We measured blood pressure (both clinic and 24-hour ambulatory recording), left ventricular mass (echocardiography), and carotid artery wall thickness (B-mode ultrasound); we assessed the AT1 receptor genotype by polymerase chain reaction and allele-specific oligonucleotide hybridization. Blood pressure values were lower in CC homozygotes than in heterozygotes and AA homozygotes; the difference was statistically significant for clinic measurements (mean difference for mean blood pressure, -6.6 mm Hg, P = .01; 95% confidence interval, -1.6 to -11.7 mm Hg) but not for ambulatory blood pressure measurements. CC homozygotes also presented a lower incidence of a positive family history of hypertension (P = .027). No statistically significant differences among AT1 receptor A/C1166 genotypes were observed for left ventricular mass or carotid artery wall thickness. We conclude that the present study does not support a major role of the AT1 receptor gene A/C1166 polymorphism as a marker of conditions associated with increased cardiovascular risk.

Beneficial effects of one year's treatment with captopril on left ventricular anatomy and function in hypertensive patients with left ventricular hypertrophy.

This study evaluated by echocardiography (M-mode tracings, two-dimensional-guided) the effects of captopril administration for one year (25 to 50 mg twice a day, alone or in combination with hydrochlorothiazide when necessary) on left ventricular mass index, on systolic function at rest and during stress (hand grip for three minutes and cold pressor test for three minutes), and on diastolic function in 15 patients with essential hypertension (13 men and two women, aged 30 to 67 years) with left ventricular hypertrophy. In addition, supine and standing plasma catecholamine concentrations, plasma renin activity, and plasma aldosterone levels were measured. Examinations were performed during a placebo period and after three, six, and 12 months of captopril treatment. Blood pressure was significantly reduced (p less than 0.001), but heart rate did not change. Left ventricular hypertrophy was progressively reduced during treatment, mainly through reduction of left ventricular wall thickness. After one year, all patients had a normal left ventricular mass index (less than 120 g/m2). Before and during treatment, left ventricular systolic function, at rest and on maximal hand grip and cold pressor testing, evaluated on the basis of fractional shortening as related to end-systolic stress, was within the 95 percent confidence limits (calculated in a group of 25 normal subjects) in all 15 patients with essential hypertension. The percent increase in left ventricular dimensions during the diastolic rapid filling phase was significantly increased by treatment (p less than 0.05), indicating improvement of left ventricular relaxation. As expected, plasma renin activity was increased, plasma aldosterone levels were decreased, and plasma catecholamine concentrations did not change. These results indicate that long-term treatment with captopril has beneficial effects on left ventricular anatomy and function in patients with essential hypertension.

Gene expression of cardiac beta 1-adrenergic receptors during the development of hypertension in spontaneously hypertensive rats.

OBJECTIVE: To study adrenergic receptors in the heart tissues of genetically hypertensive rats by evaluating the gene expression and the membrane protein density of beta 1-adrenergic receptors using steady-state messenger RNA (mRNA) levels and a radioligand binding assay, respectively. DESIGN: We compared prehypertensive (5-week-old) and early-hypertensive (13-week-old) spontaneously hypertensive rats (SHR) with age-matched Wistar-Kyoto (WKY) normotensive control rats. METHODS: Polyadenylated RNA was extracted from individual hearts and analysed by the slot-blot technique using a beta 1-adrenergic receptor complementary DNA probe. beta-Adrenergic receptors in myocardial membranes were studied by radioligand binding assay using [125I]-cyanopindolol and the beta 1- and beta 2-selective antagonists CGP 207.12A and ICI 118.551, respectively. RESULTS: beta 1-Adrenergic receptor mRNA levels were slightly higher, and membrane protein density was similar in prehypertensive SHR and age-matched WKY rats. However, both beta 1-adrenergic receptor mRNA levels and beta 1-adrenergic receptor density were lower in the hypertensive SHR than in the control rats. beta 1-Adrenergic receptor mRNA was significantly reduced in older rats of both strains, and this reduction was most evident in the SHR. CONCLUSIONS: The absence of downregulation of beta 1-adrenergic receptors in young SHR, despite published data indicating a higher cardiac noradrenaline turnover than in WKY rats, may suggest that the cardiac hyperadrenergic activity observed in prehypertensive SHR is maintained, at least in part, by the participation of peripheral, postsynaptic component(s) involving beta 1-adrenergic receptor dysregulation. In addition, the present data suggest that the previously reported evidence of an age-related decrease in cardiac beta 1-adrenergic receptors in rats may be determined at the transcriptional level.

Relationship between sympathetic nervous system activity, baroreflex and cardiovascular effects after acute nitric oxide synthesis inhibition in humans.

OBJECTIVE: To examine the cardiovascular effects of acute systemic nitric oxide synthesis inhibition in humans in relation to the possible involvement of changes in sympathetic nervous system activity or in the baroreceptor reflex. DESIGN: Placebo or NG-monomethyl-L-arginine (250 mg by intravenous infusion for 5 min) was administered to seven healthy male volunteers according to a random, double-blind sequence. METHODS: Blood pressure and heart rate were measured non-invasively using a Finapres device from 20 min before to 80 min after starting infusion; beat-to-beat variability of blood pressure, pulse interval and systolic blood pressure and pulse interval covariation were assessed by means of spectral and sequence analysis methods. Under basal conditions and 15 min and 60 min after infusion, we measured stroke volume and indices of cardiac systolic and diastolic function by echocardiography, forearm blood flow by strain-gauge venous occlusion plethysmography, and plasma catecholamine levels. RESULTS: Compared with placebo, administration of NG-monomethyl-L-arginine caused a transient increase in blood pressure and reduction in heart rate. Stroke volume and indices of cardiac function did not change significantly, whereas cardiac index and forearm blood flow were significantly reduced after 15 min. Spectral analysis of blood pressure and pulse interval showed a significant reduction of power spectral density in the low frequencies (0.03-0.15 Hz) that persisted 60 min after infusion. The plasma noradrenaline level was significantly reduced after 15 min. No change in baroreflex engagement or sensitivity was detected by the cross-spectral or the sequence method. CONCLUSIONS: Acute systemic nitric oxide synthesis inhibition transiently increases blood pressure and reduces heart rate and cardiac index. The acute hypertensive response to NG-monomethyl-L-arginine is dependent neither on sympathetic nervous system activity, which is probably reduced as a consequence of baroreceptor reflex activation, nor on baroreceptor reflex sensitivity, which is not impaired.

Alpha-adducin gene polymorphism and cardiovascular phenotypes in a general population.

BACKGROUND: Previous studies have shown that molecular variants of the cytoskeletal protein adducin may be involved in regulation of blood pressure both in genetic rat hypertension and in human essential hypertension. OBJECTIVE: To investigate the relationship of genetic polymorphism of alpha-adducin with blood pressure, cardiovascular structure, and some biochemical indexes of cardiovascular risk in a sample of general population. DESIGN AND METHODS: A sample of 246 subjects (124 men and 122 women, aged 57.7+/-3.7 years) was randomly chosen from a middle-aged population. Twenty-four-hour ambulatory blood pressure, as well as left ventricular mass (by echocardiographic methods) and carotid wall thickness (by B-mode ultrasound methods) were measured. DNA was extracted from peripheral blood samples; the Gly460Trp diallelic variant of human alpha-adducin was genotyped by polymerase chain reaction amplification and then allele-specific oligo hybridization. RESULTS: A trend toward higher 24 h ambulatory blood pressure values in subjects not treated with antihypertensive drugs was observed among carriers of Trp460 allele, although the differences did not attain statistical significance (at closest, P = 0.066 for a dominant effect of Trp460 on systolic blood pressure). When blood pressure was considered a dichotomous variable, allowing the inclusion of treated hypertensives), a higher prevalence of Trp460 allele among hypertensives was observed (0.188 versus 0.106 among normotensives, P= 0.02). There was no evidence of association either of left ventricular mass or of common carotid wall thickness with Gly460Trp polymorphism. CONCLUSIONS: In this sample of a general population, the relationship of a genetic polymorphism of alpha-adducin with blood pressure values was rather weak. However, a population-based case-control analysis indicated that there was an association between Trp460 allele and hypertension, with a relative risk for subjects carrying at least one Trp460 allele of approximately 1.6. Further investigation of larger and different population samples in order to assess the role of adducin gene polymorphism as a marker of genetic predisposition to the development of hypertension is warranted.

Adrenergic activity and left ventricular function during treatment of essential hypertension with calcium antagonists.

The effects of 2 calcium antagonist drugs, verapamil and nifedipine, on blood pressure, heart rate (HR), plasma catecholamines, plasma renin activity and some echocardiographic indexes of left ventricular anatomy and function were studied in 67 patients with essential hypertension. The short- and long-term antihypertensive effect of verapamil was not associated with significant changes in HR, plasma catecholamines or plasma renin activity; the decrease in blood pressure after nifedipine was associated with a significant increase in HR and plasma catecholamines (mainly noradrenaline) (p less than or equal to 0.05). These findings were confirmed in a crossover comparison in 12 hospitalized patients treated with verapamil and nifedipine for 8 days each. The dose of isoproterenol that increased HR by 25 beats/min was significantly increased during verapamil treatment (p less than 0.05) and decreased during nifedipine treatment (p less than 0.01). Stroke volume and shortening fraction increased slightly but significantly (p less than 0.05) with 3 months of nifedipine treatment, while no change was detected with verapamil treatment. Left ventricular mass was significantly decreased after effective antihypertensive treatment for 3 months with verapamil or nifedipine (p less than or equal to 0.05).

Angiotensin-converting enzyme inhibition, catecholamines and hemodynamics in essential hypertension.

Captopril was given to 15 unselected patients with essential hypertension (WHO II) at a dose range of 300 to 600 mg/day. Hemodynamic indexes (thermodilution) as well as levels of plasma norepinephrine, epinephrine, renin activity and aldosterone were determined simultaneously at the end of 2 weeks of placebo and after 8 weeks of captopril treatment. Systolic and diastolic arterial pressures were reduced significantly by treatment both supine (p less than 0.0025) and standing (p less than 0.0025). The diastolic arterial pressure was normalized (less than 95 mm Hg) in five patients and significantly reduced in four, whereas six patients were considered poor responders (mean arterial pressure decrease 10 mm Hg or less). The decrease in arterial pressure correlated significantly with the reduction in total peripheral resistance (r = 0.71), whereas cardiac index did not change and stroke index increased because of a slight decrease of heart rate. Plasma and urinary norepinephrine and epinephrine did not change during treatment. Moreover, the response of both heart rate and plasma catecholamines to upright posture was not altered by captopril treatment. Plasma renin activity increased and plasma aldosterone concentration decreased during treatment. These results suggest that inhibition of converting enzyme activity by captopril induces a reduction in arterial pressure through a reduction in total peripheral resistance. There was no evidence of an appreciable reduction in sympathetic nervous system activity during therapy.

Renal and hemodynamic effects of atrial natriuretic peptide infusion are not mediated by peripheral dopaminergic mechanisms.

The possible involvement of peripheral dopaminergic mechanisms in the action of atrial natriuretic peptides was investigated in 10 subjects by administering 200 micrograms h-ANP 99-126 intravenously for 30 min during treatment with 50 mg carbidopa, a peripheral inhibitor of dopamine synthesis, every 8 h, or during placebo. Atrial natriuretic peptide (ANP) infusion during placebo was associated with a significant increase of diuresis, natriuresis, kaliuresis, urinary noradrenaline, and dopamine excretion. Plasma aldosterone significantly decreased. Blood pressure was slightly reduced. The administration of carbidopa significantly reduced urinary dopamine excretion but did not modify natriuresis, diuresis, indexes of adrenergic and renin-aldosterone system activity, blood pressure, or heart rate, both in basal conditions and in response to ANP infusion. We conclude that the effects of exogenous ANP administration are independent from dopaminergic mechanisms that involve the synthesis of dopamine outside the central nervous system, particularly in the kidney.

Reduction of left ventricular hypertrophy after longterm antihypertensive treatment with doxazosin.

The aim of this study was to evaluate the effect of antihypertensive treatment with doxazosin on left ventricular anatomy and function. Therefore, after 4 weeks of washout with placebo (phase 1), doxazosin (dosage range from 1 to 16 mg, plus hydrochlorothiazide when necessary) was given to 11 essential hypertensive patients (6 M, 5 F, age range 34-63 years) for 8 weeks (phase 2) in order to achieve diastolic blood pressure values less than 90 mmHg; this dosage was then maintained for a further 20 weeks up to the end of the study (phase 3). Blood pressure was significantly reduced (Anova P less than 0.05), while heart rate did not change. A significant reduction of left ventricular mass index (from 128.5 +/- 26 to 114 +/- 23 g/m2, at the end of phase 1 and 3 respectively, P less than .001)) was observed. Before and during treatment left ventricular systolic function, both at rest and during stress (handgrip and cold pressor tests), evaluated by fractional shortening as related to end-systolic stress, in every case within 95% confidence limits, was calculated in normal subjects. Diastolic function, as evaluated by the ratio between peak early and atrial velocities of transmitral flow examined by pulsed doppler was significantly improved. Plasma catecholamine concentrations, plasma renin activity and plasma aldosterone did not change. A significant reduction of plasma cholesterol concentration was observed. These results confirm that doxazosin is a well tolerated and effective antihypertensive drug, with a favourable effect on blood lipids and they indicate that its longterm administration can induce a significant reduction of left ventricular mass.

[Conservative treatment using mesalazine in ischemic colitis]. / La terapia conservativa con mesalazina nella colite ischemica.

The authors propose the conservative treatment of ischemic colitis using slow-release mesalazine and enema. The excellent tolerability of the treatment and the good level of therapeutic efficacy was confirmed in 13 cases treated without signs of recurrence of disease.

[Coronary risk stratification and aspects of decision making after infarction]. / Stratificazione del rischio coronarico ed aspetti decisionali del postinfarto.

The prognosis of myocardial infarction has considerably and favourably changed over the last decades thanks to new procedures in the hospital and post-discharge management. The identification of high-risk patients exposed to recurrent coronary events allows more appropriate treatment of these subjects and significantly contributes to the observed improvement in the general prognosis. In this short review, we examine different procedures for prognostic assessment in myocardial infarction and discuss a strategy for a favourable cost/benefit ratio in their utilization.

[Hemodynamic and humoral effects of 2 different doses of ketanserin in aged patients with hypertension]. / Effetti emodinamici ed umorali di due diverse dosi di ketanserina in pazienti anziani ipertesi.

The purpose of this double blind, cross-over, randomized study was to assess the antihypertensive efficacy and tolerability of ketanserin given at two different doses (i.e. 20 or 40 mg b.i.d.) in a group of patients with essential hypertension aged over 60 years. In addition, we evaluated the effect of ketanserin on some indexes of the sympathetic nervous system activity and the renin-angiotensin-aldosterone system, as well as the pharmacokinetic characteristics of the drug after acute administration per os and during chronic treatment. Twelve hypertensive patients, 6 males and 6 females gave their informed consent to the study. Each patient underwent a non invasive blood pressure monitoring after a wash out period with placebo, after 5 weeks of treatment with ketanserin (20 or 40 mg b.i.d.), after a second wash out period with placebo, and after a second period of treatment (5 weeks) with ketanserin (40 or 20 mg b.i.d.). In addition, we evaluated ketanserin plasma levels during acute and chronic administration. During treatment with ketanserin 20 mg b.i.d. systolic and diastolic blood pressure showed a small, statistically not significant reduction. The higher dose (40 mg b.i.d.) reduced systolic and diastolic blood pressure. Three hours after administration of 40 mg of the drug, ketanserin plasma levels were higher than after administration of 20 mg; this difference disappeared after 24 hours. A statistically significant relationship between mean blood pressure reduction during chronic treatment and ketanserin plasma levels was detected. No adverse effects were detected. In conclusion, ketanserin seems to be well tolerated and useful in antihypertensive therapy in elderly patients, particularly at the dose of 40 mg b.i.d.

[Prosthetic repair of inguinal and crural hernias]. / La riparazione con protesi delle ernie inguinali e crurali.

335 inguino-femoral hernias were repaired with polypropylene mesh from December 1991 through December 1995. Eleven patients underwent mesh reinforced Bassini, 167 modified Lichtenstein's technique and 108 Trabucco's repair. Forty-three patients were treated under regional anesthesia. Bilateral hernia was diagnosed in 33 patients and in 20 out of 33 the surgical procedure was entirely performed under regional anesthesia. Early complications referred were 32 scrotal hematomas which spontaneously healed. Two patients showed a recidive hernia and were retreated with and additional mesh; plug rejection (early experience) was referred in one patient who was reoperated on employing a mesh. The indications for the more suitable technique were directly deducted from Nyhus' hernia classification. The authors finally point out the: 1) importance of regional inguinal anesthesia; 2) correct cutting and application of the mesh in the inguinal canal; 3) internal inguinal ring repair; 4) bilateral hernia repair under regional anesthesia.

Cardiovascular and hormonal responses to DDAVP before and after beta-blockade in patients with mild essential hypertension.

The aim of this study was to assess the cardiovascular and hormonal responses to 1-desamino-8,D-arginine vasopressin (DDAVP) in hypertensive patients before and after non-selective beta-blockade. We infused DDAVP at 400 ng/kg body weight for 10 min in nine subjects with mild essential hypertension before and 14 days after administration of nadolol at 80 mg/day. Blood pressure and heart rate were recorded, and blood was drawn at 0, 30 and 60 min for measurement of plasma renin activity, aldosterone, cortisol, noradrenaline, adrenaline and dopamine. Before the administration of nadolol, DDAVP induced a significant decrease in blood pressure, and significant increases in the heart rate, plasma renin activity, cortisol and noradrenaline; there were no changes in adrenaline or dopamine. After the administration of nadolol, baseline noradrenaline was significantly increased, while cortisol, adrenaline and dopamine remained unchanged. A second infusion of DDAVP did not significantly alter blood pressure, [corrected] heart rate, noradrenaline, adrenaline or dopamine, but plasma renin activity, aldosterone and cortisol still showed a significant increase. The blunted hypotensive effect of DDAVP after the administration of nadolol may be aspecific, due to lower basal blood pressure levels, or may indicate a mechanism of action common to both drugs. A similar post-DDAVP increase before and after beta-blockade suggests that the drug has a direct effect on the renin-secretory apparatus. An indirect effect, mediated by changes in intrarenal haemodynamics or by other factors with renin-stimulating activity, e.g. tissue plasminogen activator, can also be hypothesized.

Long-term antihypertensive treatment may induce normalization of left ventricular mass before complete regression of vascular structural changes: consequences for cardiac function at rest and during stress.

In 14 essential hypertensive patients, aged 26-59 years, blood pressure, left ventricular mass index (LVMI), systolic function (M-mode echo, two-dimensionally guided), post-ischaemic 'maximal' forearm blood flow (strain gauge venous occlusion plethysmography), plasma renin activity, plasma catecholamines and aldosterone were measured before and after 6 and 12 months of treatment (eight patients were given captopril, 100 mg/day, + hydrochlorothiazide 25 mg/day in five patients, and six patients were given nitrendipine, 20 mg/day, + atenolol 50 mg/day in four patients). Minimal vascular resistance (mean blood pressure/peak forearm blood flow) was taken as an index of arterial structural changes. After 6 months of treatment significant reductions in blood pressure (P less than 0.001), LVMI (P less than 0.001) and minimal vascular resistance were observed. After 12 months of treatment blood pressure, LVMI and minimal vascular resistance were further reduced. The LVMI was normalized in nine cases and the minimal vascular resistance in two cases only. Aldosterone and plasma catecholamines did not change, whereas plasma renin activity was increased during captopril only. Before and during treatment the left-ventricular shortening fraction in relation to end-systolic stress in each patient at rest, and at peak of handgrip and cold pressor tests, fell within the 95% confidence limits of correlation obtained in normals. Thus, in essential hypertensives long-term treatment can induce normalization of LVMI before complete regression of arterial structural changes in the forearm. Left ventricular systolic function is preserved after normalization of LVMI, both at rest and during stress.