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R Rizzi

Publications and source records attributed to R Rizzi.

At least 19 recordsLinked to original sources
PubMed2004

Postnatal stress in mice: does "stressing" the mother have the same effect as "stressing" the pups?

Short- and long-term effects of brief maternal separation, maternal exposure to novel male odor, and standard rearing were compared in NMRI mice. The first condition consisted of 15 min of daily exposure of pups to clean bedding (CB), and the second condition consisted of 15 min of mothers' exposure to the odor of strange males (SM), for 14 days after birth starting from postnatal Day 1. Thus, both conditions entailed the same period of maternal separation. A control mother-offspring group was left undisturbed (nonhandled, N-H). Corticosterone levels of mothers and pups were measured at the end of the last manipulation session. Corticosterone levels were higher in SM mothers, differing from both those of CB and of control dams; CB pups showed the highest corticosterone levels in comparison with the pups belonging to the other groups. Maternal behavior observed as furthest as possible from the daily separation session did not differ among the three groups. The behavioral response to 0.5 mg/kg of apomorphine in 15-day-old pups was enhanced in both CB and SM animals, which suggests an alteration of dopaminergic functioning. Finally, adult CB and SM male mice showed an increase in the percentage of time and entries into the open arms of the plus-maze in comparison to nonhandled males. This study indicates that exposure to ecologically relevant stimuli elicited a stress response in lactating dams. This "social stress" brings about short- and long-term effects in the offspring, even in the absence of any direct manipulation of the pups.

Animals↗
PubMed2003

FLAG-IDA in the treatment of refractory/relapsed acute myeloid leukemia: single-center experience.

We evaluated the efficacy and toxicity profiles of the combination of fludarabine, high-dose cytosine arabinoside (AraC), idarubicin, and granulocyte colony-stimulating factor (G-CSF) in refractory/relapsed acute myeloblastic leukemia (AML) patients. Between October 1998 and February 2002, 46 AML patients were treated with FLAG-IDA (fludarabine 30 mg/m(2), AraC 2 g/m(2) for 5 days, idarubicin 10 mg/m(2) for 3 days, and G-CSF 5 micro g/kg from day +6 until neutrophil recovery). Thirty patients were in relapse after conventional chemotherapy including cytarabine, etoposide, and daunorubicin or mitoxantrone according to the GIMEMA protocols. Four were in relapse after autologous peripheral stem cell transplantation and two after allogeneic bone marrow transplantation. Ten patients had refractory disease (after 10 days of standard doses of cytarabine, 3 days of mitoxantrone or daunorubicin, and 5 days of etoposide). Recovery of neutrophils and platelets required a median of 19 and 22 days from the start of therapy. Complete remission (CR) was obtained in 24 of 46 patients (52.1%) and 3 of 46 (6.6%) died during reinduction therapy: 2 due to cerebral hemorrhage and 1 due to fungemia ( Candida tropicalis). Fever >38.5 degrees C was observed in 40 of 46 patients (86.9%), 27 had fever of unknown origin (FUO) and 13 documented infections; 31 of 46 (67.3%) developed mucositis and 14 of 46 (30.4%) had grade 2 WHO transient liver toxicity. After achieving CR, 11 patients received allogeneic stem cell transplantation, 4 patients received autologous stem cell transplantation, 4 were judged unable to receive any further therapy, and 5 refused other therapy. Ten patients are at present in continuous CR after a median follow-up of 13 months (range: 4-24). In our experience, FLAG-IDA is a well-tolerated and effective regimen in relapsed/refractory AML. The toxicity is acceptable, enabling most patients to receive further treatment, including transplantation procedures.

Adolescent↗
PubMed2001

A model of social stress in dominant mice: effects on sociosexual behaviour.

The possibility of socially stressing the dominant/aggressive member of a pair of male mice is tested. Male mice (NMRI outbreed strain) were housed in pairs to assess dominant and subordinate roles by agonistic interactions and urine-marking test. Social stress for dominant males consisted in 30 min/day of exposure to their subordinate partner interacting with a female in the adjacent compartment of the cage, for 9 days. Results showed that dominance status was maintained. Behavioural observations indicated that neither the subordinates nor the dominant males habituated to this experimental procedure. At the end of the chronic stress, dominant animals were given the opportunity to interact for 30 min with a female in their compartment. Results indicated that stressed dominants showed impairment in their sexual behaviour and were more oriented towards the physical environment in comparison with control dominants. The behavioural response to apomorphine (0.25 mg/kg) indicated an alteration of the dopaminergic functioning in socially stressed dominant mice. This study suggests that the characteristics of the stressor and the effects of the chronic social stress could be different, according to male social status.

Animals↗
PubMed2001

Flow injection analysis of L-lactate in milk and yoghurt by on-line microdialysis and amperometric detection at a disposable biosensor.

A disposable lactate biosensor able to operate in flow injection analysis is described and characterized. The biosensing layer, obtained by glutaraldehyde co-crosslinking of lactate oxidase with bovine serum albumin, was cast on an underlying electropolymerized layer of overoxidized polypyrrole. The resulting biosensor was interference-free and showed a K'M value of 2.4 mmol l-1 and a maximum current density of 440 microA cm-2. When integrated in a flow injection analysis system, a sensitivity of 300 +/- 10 nA mmol-1 l, a linear response up to 1 mmol l-1 and detection limits in the low micromolar range were obtained. The introduction of a microdialysis membrane-based sampler reduced the sensitivity to 7.9 +/- 0.2 nA mmol-1 l and extended the linear range up to 50 mmol l-1 lactate. The anti-interference characteristics of the biosensor permitted lactate determination in untreated milk and diluted yoghurt samples.

Animals↗
PubMed2001

The effect of the eradication of Helicobacter pylori infection on hemorrhage because of duodenal ulcer.

The cost of a recurrently bleeding duodenal ulcer (DU) is very high, both from a human and an economic point-of-view. Helicobacter pylori infection plays an important role in the pathogenesis of DU disease and its complications, such as bleeding. Cure of H. pylori infection is recommended in patients with DU and its complications, although in the latter case, the most efficient management is not yet a defined issue. In particular, acid secretion inhibitors may not contribute to long-term cure. Our aims were to ascertain whether the recurrence of bleeding because of DU could be prevented by H. pylori eradication and whether long-term inhibition of gastric acid output is needed to prevent recurrence. Eighty-four patients (65 men; mean age, 55.1 years), who had bled because of recurrent DU, were followed after the cure of H. pylori infection. None of the patients were on therapy with nonsteroidal antiinflammatory drugs. Successful cure of H. pylori was determined by gastroscopy, histology, and serology performed at 3, 6, 12, 24, and 48 months after the eradication treatment. A 13C urea breath test was performed when the results of serology were unclear and also at recurrence of DU or bleeding. After the antibiotic treatment, 46 patients stopped all medications, whereas 38 continued long-term therapy with histamine type 2 receptor antagonists. During a mean follow-up period of 47.2 months (range, 37-65 months), recurrence of DU at endoscopy was observed in three patients in each group (p = 0.56), but none bled again. We conclude that H. pylori eradication prevents DU recurrence and rebleeding, that reinfection rate by H. pylori after cure was nil at 4 years, and that long-term inhibition of acid secretion may not improve outcome after cure of H. pylori, even in patients whose DU was complicated by hemorrhage.

Duodenal Ulcer↗
PubMed2001

Angiogenesis and hereditary hemorrhagic telangiectasia. Rendu-Osler-Weber disease.

To date much of the recent work on pathological angiogenesis has focused on inflammatory diseases, diabetes and cancer in particular. Hereditary hemorrhagic telangiectasia or Rendu-Osler-Weber disease provides an example of the genetic disorder of angiogenesis in which a multisystemic angiodysplasia is responsible for severe hemorrhage. The disease pathogenesis is partially explained by a defect in the TGF-beta signaling system, although in more recent works a possible role of other vascular growth factors has been proposed. This paper provides a model of an aberrant angiogenesis in which multiple vascular growth factors could be involved in a diffuse angiodysplasia.

Activin Receptors, Type I↗
PubMed2000

Synthesis, X-ray powder structure, and magnetic properties of the new, weak ferromagnet iron(II) phenylphosphonate.

A new molecule-based weak ferromagnet of formula Fe[C6H5PO3].H2O was synthesized. It was characterized by thermogravimetric analysis and UV-visible and infrared spectroscopy, and the magnetic properties were studied using a superconducting quantum interference device magnetometer. The crystal structure of the compound was determined "ab initio" from X-ray powder diffraction data and refined by the Rietveld method. The crystals of Fe[C6H5PO3].H2O are orthorhombic, space group Pmn2(1), with a = 5.668(8) A, b = 14.453(2) A, c = 4.893(7) A, and Z = 2. The title compound is isostructural with the previously reported lamellar M[C6H5PO3].H2O, M = Mn(II), Zn(II), and Cd(II). The inorganic layers are made of Fe(II) ions octahedrally coordinated by five phosphonate oxygen atoms and one from oxygen of the water molecule. These layers are then separated by bilayers of the phenyl groups, and van der Waals contacts are established between them. The refinement has shown that the phenyl rings are disordered in the lattice. The oxidation state of the metal ion is +2, and the electronic configuration is d6 (S = 2) high-spin, as determined from dc magnetic susceptibility measurements from 150 K to room temperature. Below 100 K, the magnetic moment of Fe[C6H5PO3].H2O rises rapidly to a maximum at TN = 21.5 K, and then it decreases again. The peak at TN is associated with the 3D antiferromagnetic long-range ordering. Below the critical temperature, the title compound behaves as a "weak" ferromagnet, which represents the third type of magnetic materials characterized by having a finite zero-field magnetization, ferromagnets and ferrimagnets being the other two types. The large coercive field (i.e., 6400 G) observed in the hysteresis loop at T = 10 K is rare in molecule-based materials; it can be ascribed to a pronounced spin-orbit coupling for the 5T2g ground state of the Fe(II) ion in the octahedral environment.

Journal Article↗
PubMed2000

Simultaneous monitoring of glucose and lactate by an interference and cross-talk free dual electrode amperometric biosensor based on electropolymerized thin films.

An interference and cross-talk free dual electrode amperometric biosensor integrated with a microdialysis sampling system is described, for simultaneous monitoring of glucose and lactate by flow injection analysis. The biosensor is based on a conventional thin layer flow-through cell equipped with a Pt dual electrode (parallel configuration). Each Pt disk was modified by a composite bilayer consisting of an electrosynthesised overoxidized polypyrrole (PPYox) anti-interference membrane covered by an enzyme entrapping gel, obtained by glutaraldehyde co-crosslinking of glucose oxidase or lactate oxidase with bovine serum albumin. The advantages of covalent immobilization techniques were coupled with the excellent interference-rejection capabilities of PPYox. Ascorbate, cysteine, urate and paracetamol produced lactate or glucose bias in the low micromolar range; their responses were, however, completely suppressed when the sample was injected through the microdialysis unit. Under these operational conditions the flow injection responses for glucose and lactate were linear up to 100 and 20 mM with typical sensitivities of 9.9 (+/- 0.1) and 7.2 (+/- 0.1) nA/mM. respectively. The shelf-lifetime of the biosensor was at least 2 months. The potential of the described biosensor was demonstrated by the simultaneous determination of lactate and glucose in untreated tomato juice samples; results were in good agreement with those of a reference method.

Animals↗
PubMed2000

A video-polygraphic analysis of the cataplectic attack.

OBJECTIVES AND METHODS: To perform a video-polygraphic analysis of 11 cataplectic attacks in a 39-year-old narcoleptic patient, correlating clinical manifestations with polygraphic findings. Polygraphic recordings monitored EEG, EMG activity from several cranial, trunk, upper and lower limbs muscles, eye movements, EKG, thoracic respiration. RESULTS: Eleven attacks were recorded, all of them lasting less than 1 min and ending with the fall of the patient to the ground. We identified, based on the video-polygraphic analysis of the episodes, 3 phases: initial phase, characterized essentially by arrest of eye movements and phasic, massive, inhibitory muscular events; falling phase, characterized by a rhythmic pattern of suppressions and enhancements of muscular activity, leading to the fall; atonic phase, characterized by complete muscle atonia. Six episodes out of 11 were associated with bradycardia, that was maximal during the atonic phase. CONCLUSIONS: Analysis of the muscular phenomena that characterize cataplectic attacks in a standing patient suggests that the cataplectic fall occurs with a pattern that might result from the interaction between neuronal networks mediating muscular atonia of REM sleep and neural structures subserving postural control.

Adult↗
PubMed1999

The probability distribution function of structure factors with non-integral indices. III. The joint probability distribution in the P1; case.

The joint probability distribution function method has been developed in P1; for reflections with rational indices. The positional atomic parameters are considered to be the primitive random variables, uniformly distributed in the interval (0, 1), while the reflection indices are kept fixed. Owing to the rationality of the indices, distributions like P(F(p1), F(p2)) are found to be useful for phasing purposes, where p1 and p2 are any pair of vectorial indices. A variety of conditional distributions like P(|F(p1)| | |F(p2)|), P(|F(p1)| |F(p2)), P(varphi(p1)| |F(p1)|, F(p2)) are derived, which are able to estimate the modulus and phase of F(p1) given the modulus and/or phase of F(p2). The method has been generalized to handle the joint probability distribution of any set of structure factors, i.e. the distributions P(F(1), F(2),ellipsis, F(n+1)), P(|F(1)| |F(2),ellipsis, F(n+1)) and P(varphi(1)| |F|(1), F(2),ellipsis, F(n+1)) have been obtained. Some practical tests prove the efficiency of the method.

Journal Article↗
PubMed1999

Steroid-responsive multifocal demyelinating neuropathy with central involvement.

We describe 2 patients with associated central and peripheral demyelination. Electrophysiological studies revealed a demyelinating polyneuropathy with sensory and motor conduction blocks. Visual evoked potentials were abnormal. Motor evoked potentials showed abnormal central conduction time in 1 patient. Magnetic resonance imaging revealed regions of abnormal high signal in the spinal cord and brain; sural nerve biopsy disclosed a demyelinating neuropathy. Both patients showed clinical and electrophysiological improvement after steroid therapy.

Adult↗
PubMed1999

Appearance of severe jaundice after radiometabolical treatment of thyrotoxicosis.

The appearance of moderate jaundice with mildly raised levels of plasma bilirubin is an uncommon complication of thyrotoxicosis and is usually accompanied by signs of right heart failure. Some described cases were actually related, at least in part, to autoimmune chronic hepatitis. In this paper we describe a case of thyrotoxicosis accompanied by deep jaundice with very high levels of bilirubin occuring in the absence of cardiac failure and with no signs of hepatitis. Jaundice disappeared shortly after the start of thyrostatic drug treatment, supporting a possible detrimental effect of hyperthyroidism on the hepatic bilirubin metabolism.

Alkaline Phosphatase↗
PubMed1999

Takayasu's arteritis: a cell-mediated large-vessel vasculitis.

Takayasu's arteritis is an idiopathic, systemic inflammatory disease, typically involving the aorta and its main branches. Cell-mediated autoimmunity has been strongly implicated in its pathogenesis. Early or active-stage pathology consists of continuous or patchy granulomatous inflammation, which progresses to intimal and adventitial fibrosis and scarring of the media. Multiple focal or segmental stenoses result and aneurysms may occasionally occur. Clinical presentation is heterogeneous, ranging from asymptomatic to catastrophic. In some patients, constitutional signs and symptoms indicating a systemic inflammatory response are observed, usually in the early stages. Specific features reflect arterial involvement, and result from end-organ or limb ischemia; they include vascular, neurological, cardiac, and pulmonary manifestations. The course of Takayasu's arteritis usually extends for many years with varying degrees of activity. Takayasu's arteritis has a worldwide distribution, with the greatest prevalence in eastern countries. Women of reproductive age are preferentially affected, but the illness is being recognized with increasing frequency in males. Variable phenotypes are recently emerging in different ethnic groups. Diagnosis is based on clinical features and vascular imaging studies that document typical patterns of stenoses or aneurysms of the aorta and its primary branches. Assessment of the activity of Takayasu's arteritis is imprecise, in that clinical features and acute-phase reactants do not accurately reflect active blood vessel inflammation. High-dose corticosteroids alone or a cytotoxic agent in addition to a corticosteroid may be effective in treating active disease. Critical lesions may require correction by surgery or interventional radiology.

Adult↗
PubMed1998

Cerebellar ataxia, hypogonadism and chorioretinopathy: molecular analysis of an Italian family.

This study aimed to determine if cerebellar ataxia, hypogonadism and chorioretinopathy (AHCR) is associated with mutations in mitochondrial DNA or in genes responsible for spinocerebellar ataxias (SCA1, SCA2, SCA3 and Friedreich's ataxia). Two brothers with cerebellar ataxia, hypogonadism and chorioretinopathy and their unaffected parents underwent molecular analysis for duplications and deletions in mitochondrial DNA (mtDNA), point mutations in the ATP ase 6 gene, and expansions of CAG repeats (at 6p22-p23, 12q24.1, 14q32.1) and of GAA repeats (at gene X25 on chromosome 9q13). The research was negative for all mutations. Our findings confirm that AHCR is a distinct disease within the inherited cerebellar ataxias.

Adult↗
PubMed1998

Aneurysms of the supra-aortic trunks in Takayasu's disease. Report of two cases.

Takayasu's arteritis is a chronic inflammatory disease of unknown etiology, which affects the aorta and its branches. The resulting lesions can be of steno-occlusive or aneurysmatic type; the latter form is relatively rare. The authors report 2 cases which came under their observation for treatment. The first was a young man of 22 years with aneurysm of the common right carotid artery and of the subclavian left intrathoracic artery. The carotid aneurysm was operated first; arterial reconstruction was ensured by means of a dacron bypass as the saphenous vein was not usable. Three months later, exeresis of the subclavian aneurysm was performed with a left thoracotomy in the IV space. The postoperative course was uneventful and no untoward event has been observed during follow-up (15 months). The second case was a young girl of 16 years with poststenotic aneurysmatic dilatation of the anonyma artery, tight stenosis of the left renal artery and occlusion of the right renal artery. The patient underwent median sternotomy and removal of the aneurysmatic wall together with the stenosis, and a dacron patch was applied. During preoperative angiography, the stenosis of the left renal artery had been treated with PTA; one month after the first operation, a right aorto-renal bypass was fashioned with the saphenous vein. Postoperative stay was free from complications on both occasions and complete normalization of the pressure values was obtained, which persists after 12 months.

Adolescent↗
PubMed1997

Behçet's disease: an immune-mediated vasculitis involving vessels of all sizes.

Behçet's disease is an immune-mediated vasculitis affecting both small and large vessels. Small-vessel vasculitis is the pathological basis of the multiorgan involvement that results in protean clinical features. However, relapsing aphthous ulcers in the mouth are considered the clinical hallmark and are often also observed over the genitalia. Both manifestations, in association with uveitis, form the typical clinical triad. In addition, skeletal muscles, joints, gastrointestinal, cardiopulmonary, and central nervous systems can be involved. Heterogeneity in incidence, clinical manifestations, course, and severity are observed according to ethnic background. The natural course is chronic with relapses and remissions, gradually abating over the years, but the illness can also be life or sight threatening. Its origin and cause are still obscure: genetic, infectious, environmental, and immunological factors have been proposed. Owing to the lack of a specific test, diagnosis still relies on recognition of the typical clinical pattern. Treatment usually includes corticosteroids and immunosuppressive drugs. A better understanding of the pathogenesis will hopefully improve both diagnosis and therapy. In addition, the development of tests aimed at monitoring disease activity and response to therapy is certainly desirable.

Behcet Syndrome↗
PubMed1997

A neurophysiological study in children and adolescents with Crigler-Najjar syndrome type I.

We studied the neurophysiological features of five patients (age range: 4-20 years) suffering from Crigler-Najjar syndrome type I (CNsI) by means of multimodal (brainstem, somatosensory, motor) evoked potentials and periodic EEG-polygraphic recordings (follow-up: 3 months-4.5 years). Two patients presented with neurological disturbances, consisting mainly of mental slowing, motor impairment and seizures. Both of them presented an abnormal EEG, characterized by slowing of background activity associated with paroxysmal discharges. Liver transplantation was performed in one of these two patients and was followed by improvement of both the neurological picture and EEG activity. In a third patient, clinically normal, after two years of follow-up, the EEG started to show paroxysmal activity during sleep or when evoked by intermittent photic stimulation. In these three patients, multimodal evoked potentials were unremarkable. The remaining two younger subjects did not show any clinical or EEG abnormality. Our findings suggest that, whereas in newborns and infants evoked potentials have been demonstrated as reliable techniques to monitor bilirubin neurotoxicity, in children and adolescents with CNsI, EEG seems to be more sensitive in evaluating patients for neurological damage and effectiveness of therapeutic strategies adopted.

Adolescent↗