Biomedical subjects

G Donati

Publications and source records attributed to G Donati.

At least 19 recordsLinked to original sources

PubMed2006

[Frequency of recurrence after Verteporfin photodynamic therapy in AMD].

INTRODUCTION: Photodynamic treatment (PDT) with verteporfin is used to treat choroidal subfoveal neovascularization in age-related macular degeneration (AMD). However, the impact of recurrence after PDT on functional results has not been assessed, although it was previously shown to be higher than 50% after thermal laser treatment for juxtafoveal lesions, and visual prognosis was dramatically worsened by recurrence of choroidal neovascularization. METHOD: Sixty-nine consecutive patients treated with PDT for CNV in AMD were followed every 3 months for up to 3 years. RESULTS: The observed recurrence rate was 17.4%. Recurrence was not associated with a decrease in visual acuity The average number of treatments was 3.0, increasing to 4.9 in case of recurrence. CONCLUSION: The recurrence rate is significantly lower after PDT than after thermal laser. It does not have a negative impact on functional outcome.

Choroidal Neovascularization↗

PubMed2006

Prevalence of visual handicap in the elderly institutionalised population in the Geneva area.

PURPOSE: The aim of this study was to establish the prevalence of visual impairment in the elderly population in geriatric homes in an urban area. PATIENTS AND METHODS: A sample of 96 patients from 8 geriatric homes ["Etablissements Médico-Sociaux" (EMS)] in the Geneva area were examined. The NEI-VFQ-25 modified questionnaire was used. Visual acuity examination (far and near), contrast visual acuity measurement and enlargement need were administered by low vision trainers. RESULTS: Of the 96 patients 42 % were partially sighted and 3 % blind. Self assessment of visual performance disclosed that 31 % of the patients complained about bad vision but only 12 % were worried about their vision. Cataract, age-related macular degeneration, glaucoma and diabetes were the most frequent diagnosis associated to visual disability. DISCUSSION: The prevalence of the visual handicap in the elderly geriatric population is very high, but most of the patients are neither aware, nor worried about their handicap. This maybe related to associated general health disabling diseases.

Aged, 80 and over↗

PubMed2006

Molecular adsorbent recirculating system (MARS) application in liver failure: clinical and hemodepurative results in 22 patients.

PURPOSE: Acute liver failure (ALF) and acute on chronic liver failure (ACLF) still show a poor prognosis. MARS was used in 22 patients with ALF or ACLF to prolong patient survival for liver function recovery or as a bridge to transplantation. DESIGN: Evaluation of depurative efficiency, biocompatibility, hemodynamics, encephalopathy (HE) and clinical outcome. PROCEDURES: During 71 five-hour sessions we evaluated (0', 60', 120', 180', 240', 300'): bilirubin, ammonia, cholic acid (CCA), chenodeoxycholic acid (CCDCA), leukocytes, platelets, hemoglobin and mean arterial pressure (MAP). Serum creatinine, electrolytes, cardiac output, cardiac index (bioimpedence) and HE (West Haven Criteria score) were evaluated at 0' and 300'. STATISTICAL METHODS AND OUTCOME MEASURES: Student's t-test for pre- vs. end-session values was used. For bilirubin and ammonia the correlation test was made between pre- and end-session values and between pre-session values and removal rates (RRS). MAIN FINDINGS: Survival was 90.9% at 7 days, 40.9% at 30 days. Pre- vs. end-session: bilirubin from 37.2 +/- 12.5 mg/dL to 24.9 +/- 8.9 mg/dL (p < 0.01), ammonia from 88.0 +/- 60.4 micromol/L to 43.6 +/- 32.9 micromol/L (p < 0.01), CCA from 42.8 +/- 21.0 micromol/L 18.2 +/- 9.8 micromol/L (p < 0.01), CCDCA from 26.3 +/- 6.3 micromol/L to 15.7+/-7.6 micromol/L (p<0.01). The correlation test between pre-session values of bilirubin and ammonia vs. RR S was respectively 0.32 (p = 0.01) and 0.30 (p = 0.04). Leukocytes, platelets and hemoglobin remained stable. MAP increased from 82.0 +/- 12.0 mmHg to 87.0 +/- 13.0 mmHg (p < 0.05), West Haven Criteria score decreased from 2.7 +/- 0.7 to 0.7 +/- 0.7 (p < 0.001). CONCLUSION: MARS treatment led in all patients to an improvement of clinical, hemodynamic and neurological conditions, with significant reduction in the hepatic toxins blood level. Treatment biocompatibility and tolerance were satisfactory.

Acute Kidney Injury↗

PubMed2005

Fitz-Hugh-Curtis-syndrome mimicking acute cholecystitis: value of new ultrasound findings in the differential diagnosis.

Fitz-Hugh-Curtis is a rare syndrome characterised by perihepatitis following pelvic inflammatory disease. We report the case of a patient with a right ovarian teratoma, abnormal liver tests and pain in the right abdomen and shoulder, initially attributed to an acalculous cholecystitis. Before gynaecological surgery, a repeat ultrasound scan found several small avascular peritoneal masses at the upper dome of the liver, not reported in the initial examination. This prompted laparoscopic exploration of the subdiaphragmatic space, and the final diagnosis of Fitz-Hugh-Curtis-syndrome was made. Such ultrasound finding appears to be a new diagnostic feature of this syndrome.

Adult↗

PubMed2004

Diffusion MRI shows increased water apparent diffusion coefficient in the brains of cirrhotics.

BACKGROUND: Brain edema and increased intracranial pressure worsen prognosis in patients with end-stage chronic cirrhosis. OBJECTIVE: To use diffusion-weighted imaging (DWI) to quantify water apparent diffusion coefficient (ADC) in different brain regions of patients with chronic liver failure with or without hepatic encephalopathy. METHODS: The authors studied 14 patients with viral liver cirrhosis and 12 sex- and age-matched healthy volunteers. Seven patients had no clinical evidence of hepatic encephalopathy; six had grade I hepatic encephalopathy; and one had grade II hepatic encephalopathy. Brain DWI was obtained using a single-shot echo-planar imaging sequence, and four gradient strengths (b values = 0, 300, 600, and 900 s/mm(2)) were applied to calculate the average diffusivity maps. RESULTS: Mean ADC values in the brains of patients with cirrhosis were significantly increased in all selected regions of interest (caudate, putamen, and pallidus nuclei; occipital, parietal, and frontal lobe white matter) except in the thalamus. Venous ammonia was linearly related to ADC values in deep gray and white matter regions of interest. CONCLUSIONS: Brain water apparent diffusion coefficient is increased in patients with chronic liver disease and may be useful in monitoring patients with hepatic encephalopathy.

Adult↗

PubMed2004

Different haemodynamic effects of a single dose of long-acting isosorbide-5-mononitrate in healthy subjects and patients with cirrhotic portal hypertension.

BACKGROUND: The action pathways of nitrates are hypothesised to be deranged in cirrhosis. AIM: In order to confirm it, the acute haemodynamic effects of isosorbide-5-mononitrate in cirrhotic patients and controls was investigated. PATIENT: Nine cirrhotics and nine healthy controls. METHODS: Evaluation in the fasting state, 90 min after isosorbide-5-mononitrate or placebo (double-blind on two different days) and then 30 and 120 min after eating a standard meal. Various systemic and splanchnic haemodynamic parameters, including arterial impedance, assessed as Doppler pulsatility index, were measured. RESULTS: isosorbide-5-mononitrate reduced arterial pressure and increased heart rate and mesenteric pulsatility index both in controls and in cirrhotics, whereas the following parameters behaved differently in the two groups (P < 0.05): hepatic pulsatility index decreased (-9%) and the portal velocity increased (+13%) in controls, whereas hepatic pulsatility increased (+18%) and portal velocity decreased (-18%) in cirrhotics. The two groups presented a similar pattern of changes in most variables under placebo after a meal. In controls, the administration of isosorbide-5-mononitrate blunted the postprandial mesenteric vasodilation and related changes in splanchnic and systemic circulation, expected at 30 min, in comparison to those observed under placebo. In cirrhotics, instead, the postprandial pattern was similar under placebo and isosorbide-5-mononitrate. CONCLUSIONS: The acute administration of isosorbide-5-mononitrate produces different haemodynamic effects in healthy and diseased livers, both in the fasting state and after a meal, consistent with the hypothesis of a deranged response of the intrahepatic microcirculation to nitrates in cirrhosis.

Aged↗

PubMed2004

Increased prevalence of fatty liver in arterial hypertensive patients with normal liver enzymes: role of insulin resistance.

BACKGROUND: The conditions associated with fatty liver disease presenting with normal liver enzymes and the mechanism involved in its development remain to be fully elucidated. AIMS: The aim of the present study was to test the hypothesis that fatty liver with normal liver enzymes occurs more frequently in arterial hypertensive patients and to establish whether this condition is associated with insulin resistance. PATIENTS: A total of 55 non-obese, non-diabetic, non-heavy alcohol drinking patients with arterial hypertensive and normal liver enzymes and 55 sex and age matched healthy subjects were enrolled into the study. METHODS: Plasma metabolic parameters, body mass index, and the presence of fatty liver were investigated. Insulin resistance was estimated from plasma insulin and glucose as the homeostasis model assessment index. Stepwise logistic regression and multivariate regression analysis were used on the combined sample to identify variables independently associated with fatty liver and insulin resistance. RESULTS: Hypertensive patients had a significantly higher prevalence of fatty liver (30.9% v 12.7%; p<0.041), higher insulin resistance (mean 2.27 (SD 1.81) v 1.56 (0.70); p = 0.022), and slightly higher body mass index (24.9 (3.0) v 24.0 (2.2); p = 0.043) than controls. Multivariate logistic regression identified insulin resistance (odds ratio 1.66 (95% confidence interval (CI) 1.03-2.52)) and body mass index (OR 1.22 (95% CI 1.00-1.49)) as factors independently associated with fatty liver. Multivariate regression analysis showed insulin resistance to be predicted by alanine transaminase (p = 0.002), presence of arterial hypertension (p = 0.029), and body mass index (p = 0.048). CONCLUSION: The higher prevalence of non-alcoholic fatty liver in non-obese hypertensive patients with normal liver enzymes appears to be related to increases in insulin resistance and body weight.

Adult↗

PubMed2004

Endothelium and hemorheology.

Hemorheological alterations which can be found in ischaemic vascular diseases are well known and widely studied; less clear is the relationship between these alterations and endothelial function. Our studies showed that modifications in endothelial function caused by physical stress are associated with a worsening in hemorheological parameters mainly in patients affected by ischaemic vascular diseases: major vascular alterations have been found in patients with very high levels of plasma markers endothelial dysfunction. The control of the basal tone of the vessels is given by the complex interaction between vasoconstrictor and vasodilator endothelial factors and when this equilibrium is broken we have the endothelial dysfunction. From a methodological point of view we can find an endothelial dysfunction index determining the various substances produced by the endothelium, but it is very difficult to have a value which clearly identifies the real state of the endothelial alteration. The function of the NO, which is one of the more powerful endogenous vasodilators and whose synthesis is catalysed by nitric oxide synthase (NOS), can be determined by the ratio between blood concentrations of citrulline and arginine (the co-product and the precursor of the way of NO synthesis), which represents the level of activity of the enzyme. A very affordable index of the endothelial dysfunction is the asymmetric dimethylarginine (ADMA), a powerful endogenous inhibitor of NOS; in fact several studies demonstrated a strong relationship between ischaemic vascular diseases and high levels of plasma ADMA. Evaluation of these parameters is measured by means of high performance liquid chromatography (HPLC): this technique provides very affordable results and allows to obtain evaluations of substances in very small concentrations, like ADMA.

Adult↗

PubMed2003

Artificial kidney: status of the art and new perspectives.

Extracorporeal dialysis was first performed in 1943 and has become a routine for End Stage Renal Patients from the early sixties. In the last 30 years researchers have focused on biocompatibility of artificial materials and optimisation of removal of uremic toxins by the membrane as in the long term treatment many complications like amylodosis heart and bone lesions, accelerated amyloidosis and immune system failure can occur. From this point of view high flux dialytic membranes are currently considered more biocompatible therefore being able to prevent such diseases.

Biocompatible Materials↗

PubMed2003

Inflammatory response of a new synthetic dialyzer membrane. A randomised cross-over comparison between polysulfone and helixone.

Hemodialysis patients suffer from chronic inflammation due to intradialytic contact of blood with artificial materials. The FX 60 dialyzer which belongs to the new FX-class series of dialyzers is composed of the new membrane Helixone. This membrane is derived from the original Fresenius Polysulfone membrane. The FX-class design is based on modified geometry of fibres and housing and has resulted in a new dialyzer with improved efficiency, safety and ease of handling compared to the F series (F 60S) dialyzer. The aim of the study was to investigate whether the biocompatibility pattern in terms of inflammatory parameters of the new type of polysulfone dialyzer has changed compared to the standard. A clinical in vivo study was conducted to compare the intradialytic inflammatory response of the two dialyzers, FX 60 and F 60S. Eight chronic dialysis patients were selected for the study: mean age 65.5 +/- 15.5 years, mean time on dialysis 100 +/- 95 months. The randomized cross-over study involved a treatment period of 2 weeks (total 6 sessions), one week with each dialyzer, starting with one or the other according to the randomization scheme. Blood samples were taken at 0 (T0), 15, 60, and 240 minutes to evaluate white blood cell (WBC) count, complement factor C5a, leukocyte elastase, soluble intercellular adhesion molecule 1 (sICAM-1), platelet count, C-reactive protein (CRP). At 15 min, WBC count showed a comparably, low decrease for both dialyzers: -7.6% for FX 60 versus -6.6% for F 60S, p=not significant (ns). At the same time the C5a concentration decreased from 15.0 +/- 7.5 ng/ml to 13.5 +/- 6.7 ng/ml (p=ns) for FX 60, and from 15.1 +/- 12.5 ng/ml to 14.9 +/- 25.0 ng/ml for F 60S (p=ns). The elastase concentration progressively increased over time with no statistical difference between the two dialyzers. The levels of sICAM-1, CRP, and platelet count were similar at each time point for both dialyzers, varying around the baseline values (p=ns). No significant difference emerged in terms of inflammatory response between the two dialyzers, hemo demonstrating that the biocompatibility of the F-series was maintained in the FX-class series of dialyzers and is independent of design factors.

Aged↗

PubMed2003

Clinical application of sodium profiling in the treatment of intradialytic hypotension.

BACKGROUND: Intradialytic hypotension is mainly induced by the removal of extracellular sodium during dialysis, which impairs intravascular fluid refilling and reduces blood volume. To counter this complication we tested a new kind of profiled hemodialysis (PHD) consisting of the intradialytic modulation of dialysate sodium concentration according to individual profiles set up using a new mathematical model for intradialytic solutes and water kinetics. The clinical aim of this PHD is to stabilize blood pressure maintaining higher blood volume values than standard dialysis treatments. We clinically validated PHD in comparison with constant dialysate sodium dialysis (CHD). METHODS: Twenty hypotensive dialysis patients underwent one PHD and one CHD session maintaining the same dialysis length, sodium mass removal and body weight decrease. A new mathematical model was used to define both the dialysate sodium profiles for PHD and the constant dialysate sodium for CHD. Percent blood volume variation (Crit-line), mean blood pressure, heart rate, cardiac output (Doppler-echocardiography) were monitored intradialitically. RESULTS: Cardiovascular stability improved on PHD as compared with CHD sessions; blood volume and cardiac output during PHD showed a lower decrease than on CHD, the differences statistically significant (from 30' and 60' respectively). Mean blood pressure was, at all time intervals, more stable on PHD than on CHD and was accompanied, on PHD, by a lower heart rate increase (differences statistically significant). CONCLUSIONS: This study shows that PHD performed using dialysate sodium profiles elaborated by our mathematical model obtains, in hypotensive patients, a higher hemodynamic intradialytic stability than CHD, probably due to a higher stabilization of blood volume.

Aged↗

PubMed2003

[Fluticasone propionate in the treatment of airway inflammations (asthma and rhinitis)].

Inflammation is the pathogenetic basis of many airway diseases like asthma and rhinitis. This provides the rationale for a therapy with antiinflammatory drugs like inhaled corticosteroids (ICS), which are able to suppress the underlying pathologic processes, ensuring an effective control of the disease and improving patients's quality of life. Within ICS, fluticasone is endowed of a potent antiinflammatory activity, due to its high affinity for the the glucocorticoid receptor (allowing the use of 50% of the dose of other ICS) and of a negligible oral bioavailability (<1%), indicating a low potential for systemic exposure. Due to its high therapeutical index, fluticasone can be used in the management of severe asthma or other airway diseases at doses devoid of relevant unwanted systemic effects. Scientific literature has broadly demonstrated its efficacy and safety, even at high doses and in the long term use.

Adult↗

PubMed2002

Abnormal brain energy metabolism shown by in vivo phosphorus magnetic resonance spectroscopy in patients with chronic liver disease.

We used phosphorus magnetic resonance spectroscopy (31P-MRS) to assess in vivo the brain bioenergetics of 28 patients with liver cirrhosis. Seven had clinical hepatic encephalopathy (HE), nine hepatocellular carcinoma. 31P-MRS was performed by the DRESS localisation technique on occipital lobes. Brain phosphocreatine was significantly reduced in patients with or without overt HE, and inorganic phosphate was increased in both groups of patients. The cytosolic phosphorylation potential (PP), the relative rate of oxidative metabolism and the regulatory [ADP] were all abnormal. Brain PP was inversely correlated with serum ammonia concentration only in patients without liver cancer. The degree of bioenergetic failure was significantly higher in the presence of overt encephalopathy. We conclude that patients with liver cirrhosis had a derangement of brain energy metabolism, and that 31P-MRS offers a non-invasive method for investigating the underlying mechanisms of HE, with relevant implications in the identification and management of this condition.

Adenosine Diphosphate↗

PubMed2002

Influence of the spleen on portal haemodynamics: a non-invasive study with Doppler ultrasound in chronic liver disease and haematological disorders.

BACKGROUND: Splanchnic haemodynamic parameters for the differential diagnosis of splenomegalies of different origins are still suboptimal and the role of spleen enlargement in cirrhosis remains controversial. In an attempt to elucidate these questions, we assessed splanchnic haemodynamics in chronic liver diseases and various other disorders with splenomegaly. METHODS: Study groups comprised: (i) patients with chronic liver disease (89 with cirrhosis, 35 with chronic hepatitis), (ii) patients with splenomegaly without relevant portal hypertension (14 with haematological splenomegaly and 25 liver transplant recipients without complications), (iii) 15 patients with arterial hypertension, (iv) 22 healthy controls. In all subjects, spleen size, portal flow parameters and splenic artery resistance index were measured using duplex-Doppler ultrasound. RESULTS: Splenic artery resistance index was significantly and selectively increased in patients with cirrhosis (0.63, whereas all other group means ranged between 0.53 and 0.56; P < 0.01). Portal flow velocity was significantly decreased in cirrhosis (P < 0.01). The combination of these two parameters provided an accuracy of 87.5% in distinguishing portal hypertensive from haematological splenomegaly. In patients with cirrhosis, the degree of spleen enlargement was positively correlated with increasing portal flow volume, portal vein diameter and variceal size, whereas splenic resistance index and portal velocity did not differ in connection with spleen size. CONCLUSIONS: Splenoportal Doppler sonography provides specific findings in cirrhosis and may therefore be a useful tool in differentiating between splenomegaly of portal hypertensive or haematological origin. In patients with cirrhosis, the presence of splenomegaly is associated with the presence of larger oesophageal varices.

Adult↗

PubMed2002

Platelet activation and PDGF-AB release during dialysis.

During hemodialysis the blood-membrane contact causes a release of platelet granule content, which contains Platelet Derived Growth Factor (PDGF-AB). In view of its possible role in accelerated atherosclerotic processes, we evaluated the intra- and post-dialytic changes in PDGF-AB serum levels during hemodialysis sessions performed with Hemophan and Polysulfone membranes. PDGF-AB, PF4, betaTG and MPV levels were determined in the peripheral blood in 30 patients each of whom underwent 6 dialysis sessions: 3 with Hemophan (HE) membrane and 3 with Polysulfone (PS) membrane, interpolated by a wash out session with PS membrane. Blood samples were taken at times 0', 30', 120', 180', 240' during dialysis sessions and at 1, 4 and 20 hours after the end of the session. Statistical analysis was done using the ANOVA one way test and Student's t test PDGF-AB serum levels initially increased and, except for a sharp fall at 120', remained constantly high during HD with both membranes tested, not returning to basal values until 20 hours after the end of the session. PF4, betaTG and MPV all showed a similar trend to PDGF. No statistically significant difference was found between the two membranes tested. PDGF-AB, a powerful growth factor in cells of mesenchymal origin, is released during dialysis mainly as a result of the blood-membrane contact. This we found regardless of the type of dialyzer we tested, and, above all, proved to return very slowly to basal values. We speculate that the release of PDGF-AB could play a part like other atherosclerosis risk-factors in the appearance and worsening of atherosclerotic lesions in hemodialysis patients.

Aged↗

PubMed2002

[Current treatment of choroidal neovascularization in age-related macular degeneration].

Age-related macular degeneration (AMD) is currently the leading cause of severe visual acuity loss in people over the age of 50 in the Western world. Most of the visual loss is due to choroidal neovascularization (CNV). Laser photocoagulation is the only proven treatment for selected cases of AMD; however, it can only be used with less than 20% of patients at the time of diagnosis. Among experimental therapies currently being tested, photodynamic therapy has recently proven its efficacy in randomized multicenter studies for predominantly classic subfoveal pure occult type CNVs.

Aged↗

PubMed2001

Nocturnal activity in the cathemeral red-fronted lemur (Eulemur fulvus rufus), with observations during a lunar eclipse.

Several ecological and physiological factors have been suggested to structure circadian activity in cathemeral primates, i.e., those that are regularly active both day and night, but their relative importance remains controversial. We studied the nocturnal activity of a group of cathemeral redfronted lemurs (Eulemur fulvus rufus) in Kirindy Forest in Western Madagascar to examine its relationship with one environmental factor, ambient light levels, in detail. To this end, nightly travel distances and moon luminosity were determined between March and June 1996. During this transitional period between the wet and dry seasons these red-fronted lemurs were regularly active at night, and traveled significantly larger distances during full-moon nights compared to new-moon nights. The importance of ambient luminosity for nocturnal activity was highlighted by observations during a total lunar eclipse (i.e., during a full-moon night), which caused abrupt cessation of the animal's activity. Our results support the hypothesis that nocturnal activity of these cathemeral lemurs is regulated also by changes in ambient light levels.

Animals↗

PubMed2001

Value of splanchnic Doppler ultrasound in the diagnosis of portal hypertension.

The accuracy of various Doppler parameters of portal circulation in the diagnosis of relevant portal hypertension (presence of gastroesophageal varices) was prospectively validated. The following parameters were compared in 51 patients with chronic liver disease (40 with cirrhosis and 11 with chronic hepatitis): portal vein flow velocity and congestion index, hepatic and splenic arteries resistance indexes (RI), modified liver vascular index (portal flow velocity/hepatic artery RI) and portal hypertension index, a new index calculated as: [(hepatic artery RI x 0.69) x (splenic artery RI x 0.87)]/portal vein flow velocity. Highest accuracy was achieved by the splenic artery RI and the portal hypertension index (both around 75%) at cut-offs, respectively, of 0.60 and 12 cm/s(-1), which appeared to be, therefore, the most favorable parameters for the clinical practice. Their use may limit the need for endoscopy to search for varices.

Adult↗