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Biomedical subjects

R Sacchetti

Publications and source records attributed to R Sacchetti.

At least 19 recordsLinked to original sources
PubMed2006

Control of Legionella pneumophila contamination in a respiratory hydrotherapy system with sulfurous spa water.

OBJECTIVE: To evaluate the effectiveness of different disinfection treatments in a spa water system contaminated by Legionella pneumophila and associated with a case of Legionella pneumonia. DESIGN: During an 18-month period, the spa water was analyzed by taking samples from the well, the recirculation line, and the final distribution devices (nebulizers and nasal irrigators). Various attempts were made to eradicate Legionella organisms by chemical and thermal shock. The final protocol consisted of heat shock treatment at 70 degrees C-75 degrees C for 3 hours, 2 nights per week, followed by a lowering of the water temperature to 30 deg C+/-1 deg C for use in the plant. In addition, 3 times a week superheated steam (at a pressure of 1 atmosphere) was introduced for 1 hour into the nebulization machines. SETTING: A spa at which sulfurous water was used for hydrotherapy by means of aerosol and nasal irrigation. PATIENT: A 74-year-old woman with legionnaires disease. RESULTS: After the case of infection occurred, L. pneumophila was isolated from the recirculation line at a concentration of 400,000 cfu/L and from the nebulizers and nasal irrigators at levels ranging from 3,300 to 1,800,000 cfu/L. The colonizing organisms consisted of a mixture of L. pneumophila serogroup 1 (12%) and serogroup 5 (88%). The shock treatment with chlorine dioxide and peracetic acid resulted in the eradication of Legionella organisms from the recirculation line but not from the water generated from the final distribution devices. After the restructuring of the plant and the application of thermal shock protocol, an evaluation after 12 months revealed no evidence of Legionella contamination. CONCLUSION: To prevent Legionella colonization, disinfection treatment is effective if associated with carefully selected materials, good circuit design, and good maintenance practices.

Aged↗
PubMed2005

Legionella waterline colonization: detection of Legionella species in domestic, hotel and hospital hot water systems.

AIMS: An evaluation was made of the prevalence of Legionella species in hot water distribution systems in the city of Bologna (Italy) and their possible association with bacterial contamination (total counts and Pseudomonadaceae) and the chemical characteristics of the water (pH, Ca, Mg, Fe, Mn, Cu, Zn and Total Organic Carbon, TOC). METHODS AND RESULTS: A total of 137 hot water samples were analysed: 59 from the same number of private apartments, 46 from 11 hotels and 32 from five hospitals, all using the same water supply. Legionella species were detected in 40.0% of the distribution systems, L. pneumophila in 33.3%. The highest colonization was found in the hot water systems of hospitals (93.7% of samples positive for L. pneumophila, geometric mean: 2.4 x 10(3) CFU l(-1)), followed by the hotels (60.9%, geometric mean: 127.3 CFU l(-1)) and the apartments with centralized heating (41.9%, geometric mean: 30.5 CFU l(-1)). The apartments with independent heating systems showed a lower level of colonization (3.6% for Legionella species), with no evidence of L. pneumophila. Correlation analysis suggests that copper exerts an inhibiting action, while the TOC tends to favour the development of L. pneumophila. No statistically significant association was seen with Pseudomonadaceae, which were found at lower water temperatures than legionellae and in individual distribution points rather than in the whole network. CONCLUSIONS: The water recirculation system used by centralized boilers enhances the spreading of legionellae throughout the whole network, both in terms of the number of colonized sites and in terms of CFU count. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences in Legionella colonization between types of buildings are not due to a variation in water supply but to other factors. Besides the importance of water recirculation, the study demonstrates the inhibiting action of copper and the favourable action of TOC on the development of L. pneumophila.

Environmental Monitoring↗
PubMed2003

Immunomagnetic assay, classic culture method and fermentation tube test in the recovery of Escherichia coli O157 from sewage.

The diffusion of E. coli O157 was studied in the effluents of a large sewage treatment plant. Three methods were used: the Culture Method, Immunomagnetic Separation (IMS) and Fermentation Tube Test. Vero cells assay and PCR were used to assess toxin production and the presence of virulence genes. E. coli O157 were only detected using IMS and the Fermentation Tubes Test: one strain in raw sewage and 2 in a sample of disinfected effluent. The latter resulted positive for the production of verocytotoxin and possessed genes coding for vt2 and type gamma intimin. The best results were obtained with SMAC-CT-BCIG medium. The use of various different recovery techniques confirmed the difficulty involved in isolating E. coli O157 from water samples.

Bacteriological Techniques↗
PubMed2003

Detection of listeria monocytogenes in foodstuffs using chromogenic isolation media.

A study was carried out to compare two selective plating media commonly used to detect Listeria monocytogenes in food samples (Palcam and Oxford agar) with two more recently formulated chromogenic media (ALOA and Rapid'L.mono). A comparison was also made between the identification systems API-Listeria and Monocytogenes ID Discs. The results obtained from the analysis of 132 food samples showed that the chromogenic media allowed Listeria monocytogenes to be detected more rapidly and with higher levels of specificity and sensitivity. The efficiency of the Monocytogenes ID Discs test was confirmed, giving results comparable to those obtained with API-Listeria, but in a simpler and quicker manner.

Animals↗
PubMed2002

Two-year population-based molecular epidemiological study of tuberculosis transmission in the metropolitan area of Milan, Italy.

A 2-year, population-based, molecular epidemiological study was conducted in Milan, Italy, to determine the proportion of tuberculosis (TB) cases attributable to recent transmission. All strains were typed by restriction fragment length polymorphism (RFLP) analysis; clustering was considered indicative of recent transmission. Of the 581 cases, 239 (41.1%) belonged to clusters that consisted of 2 to 11 patients; 28.1% were attributable to recent transmission (number of clustered patients minus 1). Clustering was associated with multidrug-resistant Mycobacterium tuberculosis strains (74.2% of cases), AIDS (60.2%), and a history of incarceration (67.4%). The frequency of multidrug-resistant Mycobacterium tuberculosis was 5.3% overall (15.4% among AIDS patients). Among AIDS patients, infection with a resistant strain was independently associated with clustering (odds ratio, 1.32; 95% confidence interval, 1.07-1.163), while among non-AIDS patients, three factors were associated with clustering: history of incarceration (odds ratio, 2.03; 95% confidence interval, 1.41-2.92), age <30 years (odds ratio, 1.43; 95% confidence interval, 1.05-1.94), and native-born Italian nationality (odds ratio, 1.44; 95% confidence interval, 1.08-1.92). Of the 118 patients who belonged to either the smallest or the largest cluster, 19 (16.1%) reported an epidemiological link with another study patient. The results of this study highlight the need for control programs that focus on selected high-risk groups consisting primarily of HIV-infected individuals and persons with social and lifestyle risks for TB. These programs should be aimed at reducing the probability of transmission of drug-resistant TB through early identification of cases and provision of effective treatment until the individual is cured.

Adult↗
PubMed1998

Experimental development of a sensory control system for an upper limb myoelectric prosthesis with cosmetic covering.

A sensory control system based on the force-sensing resistor (FSR) for an upper limb prosthesis has been designed for application to a commercial prosthetic hand of proven reliability. In particular, FSR sensors have been used to control the strength of the grip on objects. Moreover, the problem of the object possibly slipping from the grip has been addressed by a system based on an optical sensor for detecting movement. Tests on different everyday objects have shown the feasibility of the above approach, given the constraints of the limited dimensions of the prosthesis and the presence of a cosmetic glove.

Arm↗
PubMed1998

Automatic tuning of myoelectric prostheses.

This paper is concerned with the development of a software package for the automatic tuning of myoelectric prostheses. The package core consists of Fuzzy Logic Expert Systems (FLES) that embody skilled operator heuristics in the tuning of prosthesis control parameters. The prosthesis system is an artificial arm-hand system developed at the National Institute of Accidents at Work (INAIL) laboratories. The prosthesis is powered by an electric motor that is controlled by a microprocessor using myoelectric signals acquired from skin-surface electrodes placed on a muscle in the residual limb of the subject. The software package, Microprocessor Controlled Arm (MCA) Auto Tuning, is a tool for aiding both INAIL expert operators and unskilled persons in the controller parameter tuning procedure. Prosthesis control parameter setup and subsequent recurrent adjustments are fundamental for the correct working of the prosthesis, especially when we consider that myoelectric parameters may vary greatly with environmental modifications. The parameter adjustment requires the end-user to go to the manufacturer's laboratory for the control parameters setup because, generally, he/she does not have the necessary knowledge and instruments to do this at home. However, this procedure is not very practical and involves a waste of time for the technicians and uneasiness for the clients. The idea behind the MCA Auto Tuning package consists in translating technician expertise into an FLES knowledge database. The software interacts through a user-friendly graphic interface with an unskilled user, who is guided through a step-by-step procedure in the prosthesis parameter tuning that emulates the traditional expert-aided procedure. The adoption of this program on a large scale may yield considerable economic benefits and improve the service quality supplied to the users of prostheses. In fact, the time required to set the prosthesis parameters are remarkably reduced, as is the technician's working time. This is interpreted as minor costs for prostheses manufacturers and suppliers.

Arm↗
PubMed1996

[Balanced beta--alpha-blocker treatment with carvedilol in mild-moderate arterial hypertension].

The search for the ideal antihypertensive drug is ongoing. Carvedilol is a new beta-adrenoceptor antagonist which also causes peripheral vasodilation primarily via alpha 1-adrenergic blockade. Twenty patients with mild to moderate essential hypertension and previous intolerance and side effects to other antihypertensive drugs were studied. After initial baseline assessment, patients received 25 mg carvedilol orally q.d. The treatment lasted 60 days. In our study carvedilol was well tolerated and no important side effect was recorded. Blood pressure decreased significantly to normal values, without orthostatic blood pressure decreases. Heart rate decreased significantly too, but no significant bradycardia was induced. No negative effects on serum lipids and no clinical evidence of increase in peripheral resistance were observed. Ventricular arrhythmia on Holter monitoring were significantly reduced after treatment with carvedilol.

Adrenergic alpha-Antagonists↗
PubMed1996

An evaluation of certain Salmonella detection methods in surface water.

Two different procedures were employed for detecting Salmonella spp. in environmental water samples: a rapid method (enrichment in Salmosyst Broth and plating in Rambach Agar-Merck) and a longer assay (pre-enrichment in Buffered Peptone Water, enrichment in Selenite-Cistyne Broth and plating in Brilliant Green Agar-Difco). The efficiency of microbiological tests was measured by the following criteria: recovery, sensitivity and specificity. The results analysed by the Kendall concordance coefficients demonstrated that the rapid method appeared more effective even if poorly specific.

Bacteriological Techniques↗
PubMed1995

Comparison of different selective methods for detection of Listeria species in surface water.

Tests were carried out to evaluate the efficiency of various combinations of selective enrichment and plating techniques using pure cultures of Listeria monocytogenes, Listeria seeligeri and Listeria innocua in suspension and samples of surface water. The best yields for the various Listeria spp. were obtained after a single passage in LEB (Oxoid) or LEB Buffered (Oxoid) and after using Palcam and Oxford agar (Oxoid). Palcam agar was, however, shown to be the most efficient means of detecting the Listeria spp. in the natural water samples.

Agar↗
PubMed1994

Study of the prevalence of Listeria spp. in surface water.

The quantity of Listeria species was determined in 49 samples of various types of water (river, brackish water, urban wastewater). Twenty nine strains of Listeria were isolated. These were mainly identified as Listeria monocytogenes (72,4%), but Listeria innocua, Listeria grayi, Listeria ivanohovii and Listeria welshimeri were also present. With the exception of water taken from the estuary, 74.4% of samples contained Listeria in mean concentrations of between 2 MPN/100 ml and 1320 MPN/100 ml in fresh surface water and untreated sewage respectively.

Animals↗
PubMed1994

Assessment of some selective media for the recovery of Aeromonas hydrophila from surface waters.

A comparison was made of three different growing media already proposed by some authors for the recovery of Aeromonas hydrophila in environmental water samples of various origins. The media tested were Rippey and Cabelli m Aeromonas agar, Rimler-Shotts agar and the Ryan Aeromonas Base Medium with the addition of ampicillin. The efficiency of the three media was evaluated on the basis of the following reference criteria: accuracy, selectivity and specificity. The results obtained, analyzed by calculating the Kendall concordance coefficients, demonstrated that m Aeromonas agar is the most suitable media for quantitative recovery of Aeromonas hydrophila from surface water samples even if a reduction in the total heterotrophic load of 3-logs was never obtained with this medium.

Aeromonas hydrophila↗
PubMed1983

Myxoid degeneration with prolapse and dystrophic calcification of the annulus fibrosus of the mitral valve. Pathological and clinical survey.

Two degenerations of the mitral valve apparatus, namely myxoid degeneration of the mitral cusps and necrosis with subsequent calcification of the annulus fibrosus, are extensively reviewed and discussed. Both lesions are mainly noticed in elderly patients, with the possible exception of systemic dystrophies of the connective tissue associated with metabolic disorders. The clinicopathological correlations of several cases are reported, with special emphasis on modern diagnostic procedures and their wide anatomic spectrum.

Adult↗
PubMed1982

Non-invasive assessment of changes in left ventricular relaxation by combined phono-, echo-, and mechanocardiography.

In order to investigate interrelations between early diastolic events, simultaneous apex-, phono-,f and echocardiograms were recorded in 10 normal and 55 patients with ischaemic heart disease. In normal subjects isovolumic relaxation time measured as A2 to mitral valve opening was 72 +/- 9 ms, the interval A2-0 point was 116 +/0 15 ms, and the amplitude of the f wave of the apexcardiogram relative to the total amplitude was 11 +/- 2%. In patients with a normal left ventricular end-diastolic pressure (less than 15 mmHg), isovolumic relaxation time was prolonged to 99 +/- 18 ms, A2-0 point to 162 +/- 5 ms, and the relative height of the f wave was increased to 21 +/- 4%. Isovolumic relaxation time and A2-0 point interval both showed significant inverse correlation with left ventricular diastolic pressure. Glyceryl trinitrate administration or isometric stress both caused well recognised changes in arterial pressure and cavity size. Neither had any additional effect during early diastole in normal subjects. In the patients, however, glyceryl trinitrate prolonged isovolumic relaxation time, delayed the 0 point of the apexcardiogram with respect to A2, increased the interval 0 point - f wave, and reduced the relative amplitude of the f wave. Isometric stress had the opposite effects. These changes extend beyond the end of ventricular relaxation and so are more readily explained on a mechanical basis, possibly as oscillations whose periodicity and degree of damping were increased by glyceryl trinitrate and decreased by isometric stress.

Coronary Disease↗
PubMed1982

Effect of age related changes in chamber size, wall thickness, and heart rate on left ventricular function in normal children.

We assessed the effects of age related changes in chamber size, wall thickness, and heart rate of left ventricular function in 78 normal children, aged 1 1/2 to 12 1/2 years, using computer analysis of their left ventricular echocardiograms. Left ventricular cavity size and wall thickness increased linearly with age. Left ventricular fractional shortening, percentage of wall thickening, and the ratio of end-diastolic wall thickness to cavity radius (H/R ratio) did not change with age. Peak Vcf correlated with heart rate and the decrease in heart rate with age resulted in the progressive fall in peak Vcf, while peak rate of left ventricular was thickening remained constant. The peak rate of increase in left ventricular cavity dimension in early diastole varied inversely with heart rate, but independently of cavity size, increasing throughout childhood. The peak rate of wall thinning also increased with age, correlating with wall thickness and not heart rate. Thus, age related increases in left ventricular cavity dimension and wall thickness during the rapid growth period of childhood occurred in such a way that left ventricular architecture (H/R ratio) remained unchanged. This may account for the constancy of regional and cavity systolic function. The greater dependence of diastolic cavity function on heart rate may be explained by the disproportionately greater effect of cardiac cycle length on the duration of diastole and systole.

Aging↗
PubMed1981

Valve replacement without preoperative cardiac catheterization.

During the year 1978, the decision to perform cardiac catheterization in patients with valvular heart disease was delayed until clinical and noninvasive assessment have been completed. As a result, 184 patient underwent operation without invasive studies, and 59 had elective catheterization. Another 62 patients were referred during the same period for valve replacement after routine catheterization had been performed elsewhere. Age, sex distribution, symptoms, and cause of valve disease were similar in all three groups, although we managed emergencies and second operations more frequently without catheterization. In all patients, the preoperative diagnosis was confirmed, and no unexpected pathologic process was encountered. Operative mortality was the same in all three groups, and after two years of follow-up there was no difference in survival or symptoms. No uncorrected valve lesions became apparent in uncatheterized patients. We conclude that routine catheterization is unnecessary before valve replacement but can be reserved for specific indications in some patients.

Adolescent↗