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Biomedical subjects

L Santoro

Publications and source records attributed to L Santoro.

At least 55 records · Page 3Linked to original sources

Adsorption of the organic fraction of a tannery sludge by means of organophilic bentonite.

Two different organophilic bentonites obtained by cationic exchange with benzyldimethyloctadecylammonium chloride and trimethyloctadecylammonium chloride have been used to adsorb the organic fraction of a tannery sludge. The exchange process was carried out to different extents to obtain bentonite samples with different organophilicities and different interlayer spacings. Before adsorption, the organic matter was extracted by contacting the sludge with a Ca(OH)2 saturated solution. The adsorption capacity was found to increase with the amount of ammonium salt exchanged for both bentonites, but the one exchanged with benzyldimethyloctadecylammonium chloride proved to be more active: up to about 80% TOC could be removed from the contacting solution. The adsorption of the organic matter caused a further increase of the bentonite interlayer spacing. In both cases, the adsorption isotherms were found to be of cooperative type, due to weak adsorbent-adsorbate interactions at low loading followed by increasing adsorbate-adsorbate interactions at increasing loading. The results may be applied to tannery sludge stabilization by cementitious systems.

Adsorption↗

Incidence and prognostic significance of atrial fibrillation in acute myocardial infarction: the GISSI-3 data.

BACKGROUND: Atrial fibrillation is the most common supraventricular arrhythmia in patients with acute myocardial infarction. Recent advances in pharmacological treatment of myocardial infarction may have changed the impact of this arrhythmia. OBJECTIVE: To assess the incidence and prognosis of atrial fibrillation complicating myocardial infarction in a large population of patients receiving optimal treatment, including angiotensin converting enzyme (ACE) inhibitors. METHODS: Data were derived from the GISSI-3 trial, which included 17 944 patients within the first 24 hours after acute myocardial infarction. Atrial fibrillation was recorded during the hospital stay, and follow up visits were planned at six weeks and six months. Survival of the patients at four years was assessed through census offices. RESULTS: The incidence of in-hospital atrial fibrillation or flutter was 7.8%. Atrial fibrillation was associated with indicators of a worse prognosis (age > 70 years, female sex, higher Killip class, previous myocardial infarction, treated hypertension, high systolic blood pressure at entry, insulin dependent diabetes, signs or symptoms of heart failure) and with some adverse clinical events (reinfarction, sustained ventricular tachycardia, ventricular fibrillation). After adjustment for other prognostic factors, atrial fibrillation remained an independent predictor of increased in-hospital mortality: 12.6% v 5%, adjusted relative risk (RR) 1.98, 95% confidence interval (CI) 1.67 to 2.34. Data on long term mortality (four years after acute myocardial infarction) confirmed the persistent negative influence of atrial fibrillation (RR 1.78, 95% CI 1.60 to 1.99). CONCLUSIONS: Atrial fibrillation is an indicator of worse prognosis after acute myocardial infarction, both in the short term and in the long term, even in an unselected population.

Aged↗

Dilated Virchow-Robin spaces in myotonic dystrophy: frequency, extent and significance.

To study the frequency, extent and significance of dilated Virchow-Robin spaces (VRSs) in dystrophia myotonica (DM), we evaluated the cranial magnetic resonance imaging (MRI) of 41 patients with the adult form of DM and 41 healthy controls. Dilated VRSs and white matter lesions (WMLs) were rated according to semiquantitative methods. Convexity VRSs were more frequent (68 vs. 34%; p < 0.01) and severer (median scores: 4 vs. 0; p < 0.01) in DM patients than in controls, while lenticulostriate VRSs did not show significant differences in frequency (83 vs. 70%; p > 0.05) and severity (median scores: 4 vs. 3; p > 0.05). WMLs were more frequent (66 vs. 22%; p < 0.01) and severer (median scores: 5 vs. 0; p < 0.01) in patients. Disease duration was negatively correlated with convexity VRSs and positively with lobar (centrum semiovale) WML scores. Dilated convexity VRSs might be one of the initial findings in cranial MRI of DM, preceding the appearance of lobar WMLs.

Adolescent↗

Treatment of intermittent claudication with mesoglycan--a placebo-controlled, double-blind study.

OBJECTIVE: To assess the effect of treatment with mesoglycan, a sulphated polysaccharide compound, on the walking capacity of patients with stage II peripheral arterial disease. METHODS: Non-diabetic outpatients with intermittent claudication, duplex ultrasound evidence of peripheral atherosclerosis, ankle/arm index <0.80, systolic ankle pressure >50 mmHg, and absolute walking distance (AWD) between 100 and 300 m (standardised treadmill test) were eligible. After a 5-week run-in on single-blind placebo, patients were randomised to double-blind treatment with mesoglycan, 30 mg/day intramuscularly for 3 weeks followed by 100 mg/day orally for 20 weeks, or matching placebo. All patients received low-dose aspirin and lifestyle instructions. Clinical response was defined as an AWD increase at Week 23 >50% over baseline. Health-related quality of life and ischaemic events were assessed as secondary efficacy variables. RESULTS: 242 patients were randomised and 237 were assessed for clinical response. Patients achieving clinical response were 59/118 with mesoglycan (50.0%) and 31/119 with placebo (26.1%; p <0.001). Geometric mean AWD increased from 192 to 298 m with mesoglycan, and from 192 to 238 m with placebo (p <0.001). Pain-free walking distance showed a non-significant increase with mesoglycan (p = 0.057). Changes in quality of life scores were in favour of mesoglycan. The rate of ischaemic events was 1/120 on mesoglycan and 6/122 on placebo (p = 0.053). The rate of non-ischaemic adverse events leading to treatment discontinuation was 7/120 and 4/122, respectively. CONCLUSION: Treatment with mesoglycan improves the walking capacity of patients with intermittent claudication, and might confer additional antithrombotic protection over that of aspirin.

Aged↗

Hemodynamic effects of MF 10058, a new cardioselective muscarinic M(2) receptor antagonist, in conscious dogs.

The 5-¿4-[4-(diethylamino)butyl]-1-piperidinyl¿acetyl-5H-dibenz[b, f]-azepine (MF 10058) is a new potent and selective muscarinic M(2) receptor antagonist. The hemodynamic effects of MF 10058 were investigated in conscious freely moving dogs. Placebo and three doses of MF 10058 (2, 4 and 8 mg/kg) were orally administered according to a randomised four-way crossover design. Heart rate, cardiac conduction times, systolic and diastolic blood pressure were telemetrically recorded for 12-24 h after dosing. After placebo administration, a consistent reduction over time in heart rate was observed during the night-time period (-15%, P=0.019). MF 10058 administration antagonised the nocturnal bradycardia and shortened QT interval. The effect of the drug reached statistically significance, compared to placebo, with the highest dose of 8 mg/kg (+19% on heart rate, P=0.013; -4% on QT interval, P=0.049). The effect on heart rate lasted for the entire 24-h observation period (+16%, P=0.030). Nocturnal systolic and diastolic blood pressure were not significantly affected by MF 10058. No other signs of peripheral or central cholinergic block were observed at any dose. The results of this study demonstrated that oral administration of MF 10058 produces long-lasting hemodynamic effects in the conscious dog. The drug has a therapeutic potential for the treatment of bradycardic disorders.

Animals↗

Atypical Friedreich ataxia phenotype associated with a novel missense mutation in the X25 gene.

We describe two sisters with early onset gait ataxia, rapid disease progression, absent or very mild dysarthria and upper limb dysmetria, retained knee jerks in one, slight to moderate peripheral nerve involvement, and diabetes. Molecular analysis showed that they are compound heterozygotes for GAA expansion and a novel exon 5a missense mutation (R165P). This mutation appears to be associated with an atypical but not milder Friedreich ataxia phenotype.

Adult↗

Sensory involvement in spinal-bulbar muscular atrophy (Kennedy's disease).

Spinal-bulbar muscular atrophy (SBMA) is a rare X-linked neuronopathy associated with an abnormal representation of androgen receptors in the nervous system. Standard nerve conduction and histopathological studies have disclosed the involvement of large myelinated sensory fibers in the spinal nerves of SBMA patients. Little is known about the involvement of small sensory neurons and trigeminal nerves. Laser evoked potentials (LEPs) were studied in 6 unrelated patients with SBMA; 5 of these patients also underwent trigeminal reflex recordings, and 3 a sural nerve biopsy. LEPs were markedly abnormal, indicating a dysfunction in pain pathways. Given the sparing of small fibers in the sural nerve specimens, we hypothesize a dysfunction in spinothalamic cells, possibly due to an abnormal representation of the androgen receptors. Except for the jaw-jerk, all the trigeminal reflexes were markedly abnormal. Since the afferents for the jaw-jerk have their cell body within the central nervous system instead of the ganglion, the selective sparing of the jaw-jerk indicates a trigeminal ganglionopathy.

Aged↗

Accuracy of clinical diagnostic criteria for Friedreich's ataxia.

The accuracy of the diagnostic criteria for Friedreich's ataxia proposed by Harding and by the Quebec Cooperative Study on Friedreich's Ataxia was studied in 142 patients with progressive unremitting ataxia of autosomal recessive inheritance or sporadic occurrence. Eighty-eight patients received the molecular diagnosis of Friedreich's ataxia. Traditional diagnostic criteria are characterized by high specificity, but they yield a high number of false-negative diagnoses. We suggest three levels of diagnostic certainty: (1) possible Friedreich's ataxia, defined as sporadic or recessive progressive ataxia with (a) lower limb areflexia and dysarthria, Babinski sign, or electrocardiographic repolarization abnormalities, or (b) with lower limb retained reflexes and electrocardiographic repolarization abnormalities (95% sensitivity and 88% positive predictive value); (2) probable Friedreich's ataxia as defined by Harding's criteria (63% sensitivity and 96% positive predictive value) or by Quebec Cooperative Study on Friedreich's Ataxia criteria (63% sensitivity and 98% positive predictive value); (3) definite diagnosis, molecularly confirmed.

Adolescent↗

Combination of mtDNA mutations in a patient with a mitochondrial multisystem syndrome.

We report a patient who manifested a heterogeneous clinical presentation, including hypertrophic cardiomyopathy and hypothyroidism, with initially limited central nervous system involvement, and who harbored the mitochondrial (mt)DNA A3243G mutation. MtDNA analysis also revealed deleted genomes in muscle and blood. This atypical molecular combination may have influenced the clinical phenotype.

Amino Acid Substitution↗

Identification of novel genes in late-onset Alzheimer's disease.

Four genes affecting Alzheimer's Disease (AD)(AP, PS1, PS2, and APOE) have been identified and a fifth potential gene localized to chromosome 12. Collectively, these genes explain at most half of the genetic effect in AD. Understanding the genetics of AD is critical to developing new treatments. The quest to find the remaining AD genes led us to undertake a large genomic screen using over 466 families (730 affected sibpairs) in late-onset AD. In conjunction with this increase in power, we initiated several novel approaches to identify potential AD-related genes. This included stratification of the data into an autopsy-confirmed subset of 199 AD families. Each of these targeted analyses resulted in the identification of novel regions containing potential AD genetic risk factors. Our most significant finding was on chromosome 9 in the autopsy-confirmed subset where we obtained an MLS of 4.31. These approaches, together with new methodologies such as conditional linkage analysis, generalized family-based association tests (PDT), and a new generation of genetic markers (SNPs), opens the door for additional AD gene discovery. Such strategies are necessary if we are to understand the subtle and complex threads that, woven together, create the intricate tapestry of AD.

Age of Onset↗

A novel SURF1 mutation results in Leigh syndrome with peripheral neuropathy caused by cytochrome c oxidase deficiency.

We report on a 5-year-old boy with clinical and neuroradiological evidence of Leigh syndrome and peripheral neuropathy. Skeletal muscle biopsy showed decreased cytochrome c oxidase stain. Ultrastructurally, the nerve biopsy showed a defect of myelination. Biochemical analyses of muscle homogenate showed cytochrome c oxidase deficiency (15% residual activity). SURF1 gene analysis identified a novel homozygous nonsense mutation which predicts a truncated surf1 protein.

Biopsy↗

Influence of GAA expansion size and disease duration on central nervous system impairment in Friedreich's ataxia: contribution to the understanding of the pathophysiology of the disease.

OBJECTIVE: To verify if GAA expansion size could account for the severity of the central nervous system involvement in Friedreich's ataxia (FA). METHODS: Retrospective study of 52 FA patients (mean age 26.9+/-12.1 years; mean disease duration 10.6+/-7.6 years) homozygous for GAA expansion. Median nerve somatosensory evoked potentials (SSEPs) were available in 36 FA patients, upper limb motor evoked potentials (MEPs) to transcranial magnetic stimulation in 32, brainstem auditory evoked potentials (BAEPs) in 24, and visual evoked potentials (VEPs) in 34. N20, P100, MEP amplitude, SSEP and MEP central conduction time (CCT and CMCT), P100 latency and I-III and I-V interpeak latency, and a BAEP abnormality score were correlated with disease duration and GAA expansion size on the shorter (GAA1) and larger (GAA2) allele in each pair. RESULTS: The GAA1 size inversely correlated with the N20 amplitude (r = -0.49; P<0. 01). Disease duration directly correlated with CMCT (r = 0.57; P<0.01) and BAEP score (r = 0.61; P<0.01) and inversely with MEP (r = -0.40; P<0.05) and P100 amplitude (r = -0.39; P<0.05). CONCLUSIONS: Our data suggest that central somatosensory pathway involvement in FA is mainly determined by GAA1 expansion size. Vice versa, degeneration of pyramidal tracts, auditory and visual pathways seems to be a continuing process during the life of FA patients.

Adolescent↗

Absent innervation of skin and sweat glands in congenital insensitivity to pain with anhidrosis.

OBJECTIVES: A case of a 10-year-old girl with congenital insensitivity to pain with anhidrosis (CIPA) is reported. METHODS AND RESULTS: Parents referred several hyperpyretic episodes without sweating occurring since birth, and insensitivity to pain, noticed when the child was 2 years old. Her body had many bruises and scars, bone fractures and signs of self-mutilation. Neurological examination was normal except for insensitivity to pain. Her IQ was 52. Electrical and tactile sensory nerve conduction velocities were normal. The patient was unable to detect thermal stimuli. Histamine injection evoked a wheal but not a flare; pilocarpine by iontophoresis did not induce sweat. Microneurography showed neural activity from A-beta sensory fibers while nociceptive and skin sympathetic C fiber nerve activity was absent. No small myelinated fibers and very rare unmyelinated fibers were found in the sural nerve. Immunohistochemistry showed a lack of nerve fibers in the epidermis and only few hypotrophic and uninnervated sweat glands in the dermis. CONCLUSIONS: The lack of innervation of the skin (C and A-delta fibers) appears to be the morphological basis of insensitivity to pain and anhidrosis, and is consistent with the loss of unmyelinated and small myelinated fibers in the sural nerve biopsy.

Child↗

Patterns of motor control reorganization in a patient with mirror movements.

OBJECTIVE: To explore motor control reorganization in a 40-year-old, left-handed patient with perinatally acquired mirror movements. METHODS: We performed simultaneous bilateral recordings of motor evoked potentials (MEPs) following focal transcranial magnetic stimulation (fTMS) and of central silent period (cSP) during unilateral voluntary contraction in abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. RESULTS: For both muscles the MEP study showed bilateral fast-conducting corticospinal projections from the right undamaged hemisphere, and residual contralateral projections from the left hemisphere. The cSP findings differed in the two muscles: the mirror phenomenon was bilateral in the ADM, but present only on the right side in the APB muscles; the mirror activity of right ADM and APB muscles was inhibited only by fTMS of the ipsilateral right motor cortex; the mirror phenomenon in the left ADM muscle was inhibited only by fTMS of the contralateral right motor cortex. CONCLUSIONS: Mirror movements of right APB and ADM muscles were sustained by the ipsilateral connections from the undamaged motor cortex, while the mirror phenomenon in the left ADM muscle could be explained by hypothesizing a bilateral activation of motor cortices. This previously unreported electrophysiological picture demonstrates that different patterns of motor control may realize after perinatal cerebral lesions, even in different distal muscles of the same patient.

Adult↗

Multiple mtDNA deletions: clinical and molecular correlations.

We studied six Italian patients harbouring multiple mitochondrial DNA (mtDNA) deletions in order to correlate clinical and molecular features. Earlier age at onset (17 vs 36 years), fewer ragged-red fibres (none vs 35%), and lower proportions of deleted mtDNAs (9 vs 33%) were found in one patient with autosomal recessive inheritance as compared to five with dominant transmission. Our findings add to the features associated with multiple deletions of mtDNA.

Adult↗

A refined physical and transcriptional map of the SPG9 locus on 10q23.3-q24.2.

Hereditary spastic paraplegia (HSP) is a genetically heterogeneous disorder characterised by progressive spasticity of the lower limbs. Beside 'pure' forms of HSP, 'complicated' forms are reported, where spasticity occurs associated with additional symptoms. We recently described an Italian family with a complicated dominant form of HSP (SPG9) and we mapped the gene responsible to 10q23.3-q24.2, in a 12cM interval between markers D10S564 and D10S603. The phenotypic manifestations in our family are reminiscent of those already described in a smaller British pedigree. We typed individuals from this British family using markers located in the SPG9 critical interval and haplotype reconstruction showed the disorder co-segregating with SPG9. To characterise the SPG9 region better, we constructed a contig of 22 YACs, assigned it to 18 polymorphic markers and positioned 54 ESTs. Furthermore, we searched for ESTs containing a trinucleotide repeat sequence, since anticipation of symptoms was reported in both families. Finally, analysis of a muscle biopsy specimen from one patient was normal, suggesting that, contrary to SPG7, mitochondrial disturbance could not be a primary feature of SPG9.

Biopsy↗