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Biomedical subjects

C Mari

Publications and source records attributed to C Mari.

At least 19 recordsLinked to original sources
PubMed2006

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.

Carcinoma, Squamous Cell↗
PubMed2003

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.

Aged↗
PubMed2003

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.

Adult↗
PubMed2003

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.

Animals↗
PubMed2002

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.

Adult↗
PubMed2002

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.

Coronary Artery Disease↗
PubMed2001

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.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2001

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.

Adult↗
PubMed2000

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.

3-Iodobenzylguanidine↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Adolescent↗
PubMed1999

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.

Adolescent↗
PubMed1999

[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.

Adolescent↗
PubMed1999

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.

Adolescent↗
PubMed1998

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.

Cystic Fibrosis↗
PubMed1998

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.

Administration, Oral↗
PubMed1997

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.

Bacterial Proteins↗