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Biomedical subjects

A Alberti

Publications and source records attributed to A Alberti.

At least 55 records · Page 3Linked to original sources
PubMed2001

Polymorphic microsatellites developed by cross-species amplifications in common pheasant breeds.

Genetic variability was analysed in two common breeds of pheasant (Phasianus colchicus L. 1758) by means of cross-species amplifications of microsatellite loci: 154 chicken, Gallus gallus and 32 turkey, Meleagris gallopavo, primers were tested for amplification of pheasant DNA. Thirty-six primers (25 specific for chicken and 11 for turkey) amplified pheasant DNA. Fifteen markers yielded specific products and were tested for polymorphism. Eight of them (55%) were polymorphic, with an average polymorphism of two alleles per locus. Specific polymerase chain reaction (PCR) products were sequenced; repeats were found in 11 of the 15 markers, although only two loci showed the same repeat and could be homologous to chicken ones.

Alleles↗
PubMed2001

Event-related potentials in posttraumatic headache.

OBJECTIVES: To assess impairment of cognitive functions occurring in patients with posttraumatic headache as a consequence of a minor cranial trauma in the absence of organic damage involving the central nervous system. BACKGROUND: The term posttraumatic syndrome defines a stereotypic set of symptoms following traumatic brain injury that are subjective and varied. A deficit of cognitive function and impairment of the rapid processes of learning, attention, and short-term memory have frequently been identified. Moreover, headache is the most frequent symptom reported by the patients. Due to the nature of the symptoms, a great limitation in defining the posttraumatic syndrome is represented by the lack of methods and diagnostic tools that allow quantification of the subjective disturbances and evidence of the signs indicative of central nervous system involvement in this pathological condition. METHODS: Twenty-five subjects (16 women, 9 men; mean age, 28 +/- 9 years) were examined between 3 and 6 months after the traumatic event. The P300 event-related potential was recorded by an odd-ball paradigm with an acoustic modality. The patients underwent electroencephalography and brain stem auditory evoked potentials; magnetic resonance imaging was performed to exclude the presence of cerebral lesions. RESULTS: The mean latency of P300 was increased in both central electrodes (Cz and Pz) in patients with posttraumatic syndrome compared with controls (P<.001); assuming the value of mean +/- 2 SD was the cutoff point between normal and abnormal results, the P300 latency results were altered in 13 patients (52%). In the patient group, a significant correlation was demonstrated between Zung Depression Scale score and P3 and N2 wave latencies (r = 0.54, P <.004; r = 0.56, P<.003) and between Zung Anxiety Scale scores and P3 wave latencies (r = 0.46, P<.02). CONCLUSIONS: These data suggest the usefulness of the P300 event-related potential in evaluating cognitive disturbances in patients affected by posttraumatic syndrome. Alteration of cognitive potential in such patients, even in the absence of lesions detectable by neuroimaging, indicate the functional impairment of specific cerebral areas that can occur after a traumatic event.

Adolescent↗
PubMed2001

Bioavailability and antioxidant activity of some food supplements in men and women using the D-Roms test as a marker of oxidative stress.

Most antioxidants show contradictory behaviors because in the biological environment, for unpredictable reasons, they can become prooxidants. Recently, a new simple method to monitor oxidative stress in serum was developed. This test detects the derivatives of reactive oxygen metabolites (D-Roms). Hydroperoxides are converted into radicals that oxidize N,N-diethyl-para-phenylendiamine and that can be detected through spectrophotometric procedures as U.CARR. (Carratelli units). One U.CARR. corresponds to 0.8 mg/L hydrogen peroxide. In normal subjects U.CARR. values range from 250 to 300. Values outside this range indicate a modification of the prooxidant/antioxidant ratio. On the basis of this method, we tested three different formulas of antioxidants (F1, F2, F3) in 14 apparently healthy volunteers (11 men and 3 women). Formula 1 was composed of 5 mg zinc, 48 microg selenium, 400 microg vitamin A (as retinol acetate), 50 microg beta-carotene, 15 mg vitamin E (as dl-alpha-tocopheryl acetate) and 10 mg L-cysteine. Formula 2 was composed of 30 mg bioflavonoids from citrus, 30 mg vitamin C (as L-ascorbic acid), 10 mg coenzyme Q(10) and 1 mg vitamin B-6 (as pyridoxine hydrochloride). Formula 3 was composed of Formula 1 plus Formula 2. Each formula was prepared in dry capsules (formulation D1, D2, D3) or in a fluid form (formulation P1, P2, P3). Each formulation was administered for 1 wk in a crossover design. A 15% deviation of U.CARR. levels was chosen as the cut-off value for a significant change in oxidative stress. Formulas F1 and F3 reduced mean U.CARR. levels in most of the treated subjects (t test, P < 0.05), whereas F2 was not active. Fluid formulations were more active than dry formulations (chi(2) test, P < 0.05). In some cases, a slight increase in oxidative stress was detected. These minimal increases were not related to any particular antioxidant formula. In one subject only, the administration of the dry formulation (D1), increased oxidative stress to a level that reached the cut-off value. In conclusion, when antioxidants are taken in combination at low dosages they reduce oxidative stress, and little relevant prooxidant activity is detectable.

Adult↗
PubMed2001

Evidence for an association between the aetiology of cirrhosis and pattern of hepatocellular carcinoma development.

BACKGROUND: Patients with liver cirrhosis are at significant risk of hepatocellular carcinoma (HCC) that may develop as well defined nodular lesions or as more aggressive infiltrating tumours. AIM: To compare prospectively risk factors associated with nodular or infiltrating HCC in cirrhotic patients. PATIENTS AND METHODS: We studied 370 patients with cirrhosis, followed prospectively by periodic ultrasound (US) of the liver, for a mean period of 74.6 (SD 32.4) months to define the incidence and patterns of HCC development. Patients who developed HCC were compared according to tumour pattern using univariate and multivariate analysis. RESULTS: Sixty one (16.5%) patients developed HCC: HCC was classified as nodular in 49 (80.3%) and infiltrating in 12 (19.7%) according to US and computerised tomography (CT) imaging. The five and 10 year cumulative probabilities were 8.1% (95% confidence interval (CI) 5. 2%-11%) and 25.2% (15.0-35.4%) for nodular HCC and 2.1% (0.5-3.7%) and 6.9% (2.1-11.7%) for infiltrating HCC. Patients with infiltrating HCC were younger than those with nodular HCC (59.5 v 66. 2 years, 95% CI 55.2-63.8 and 64.1-68.3 years; p=0.014). Using multivariate analysis, development of nodular HCC was associated with older age (p=0.0002; relative risk (RR) 3.1; 95% CI 1.6-5.2), longer duration (p=0.09; RR 2.6; 95% CI 1.8-3.4), and more advanced stage (p=0.002; RR 2.5; 95% CI 1.3-4.5) of cirrhosis but not with the aetiology of liver disease. In contrast, development of infiltrating HCC appeared to be unrelated to age or disease duration or stage, while it was associated with hepatitis B virus infection (p=0.07; RR 3.96; 95% CI 1.1-5.2) and with hepatitis B/hepatitis C virus coinfection (p=0.0007; RR 16.9; 95% CI 3.8-36.7). CONCLUSIONS: In liver cirrhosis, we identified two patterns of HCC developing with distinct risk factors. Nodular HCC was related to the cirrhotic process per se independent of aetiological factors and may depend on the proliferative activity within regenerative nodules, while the infiltrating form of HCC was linked to hepatitis B virus infection and may reflect more direct virus induced carcinogenesis.

Adult↗
PubMed2001

Amiodarone inhibits lung degradation of SP-A and perturbs the distribution of lysosomal enzymes.

Amiodarone may induce lung damage by direct toxicity or indirectly through inflammation. To clarify the mechanism of direct toxicity, we briefly exposed rabbit alveolar macrophages to amiodarone and analyzed their morphology, synthesis, and degradation of dipalmitoylphosphatidylcholine (DPPC); distribution of lysosomal enzymes; and uptake of diphtheria toxin and surfactant protein (SP) A used as tracers of the endocytic pathway. Furthermore, in newborn rabbits, we studied the clearance of DPPC and SP-A instilled into the trachea together with increasing amounts of amiodarone. We found that in vitro amiodarone decreases the surface density of mitochondria and lysosomes while increasing the surface density of inclusion bodies, increases the incorporation of choline into DPPC, modifies the distribution of lysosomal enzymes, and does not affect the uptake and processing of diphtheria toxin but inhibits the degradation of SP-A. In vivo amiodarone inhibits the degradation of SP-A but not of DPPC. We conclude that the acute exposure to amiodarone perturbs the endocytic pathway acting after the early endosomes, alters the traffic of lysosomal enzymes, and interferes with the turnover of SP-A.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2001

Food habits in a southern Italian town (Nicotera) in 1960 and 1996: still a reference Italian Mediterranean diet?

BACKGROUND: A follow-up analysis of cohorts surveyed in the "Seven Countries Study" has provided increasing evidence of an association between diet and morbidity or mortality from coronary heart disease (CHD) and cancer. The effects of the "Mediterranean diet" on mortality is still evident in Italy, where food patterns differ significantly in different geographical areas. OBJECTIVE: To examine differences in food habits in Nicotera, one of the Italian rural areas of the Seven Countries Study, between 1960 and 1996. METHODS: In 1996, 80 subjects, 37 females and 43 males, aged 40-59 years, were examined in Nicotera assessing food intake by means of a semiquantitative questionnaire of food frequency, validated for the Italian population. In 1960, food intake of a sample of Nicotera subjects was assessed by weighed record method for three seasons. RESULTS: Food choices differed markedly between 1960 and 1996. Consumption of animal foods increased, as did that of cakes, pies and cookies and sweet beverages in both male and female groups; an increase of alcoholic beverages was observed only in females. CONCLUSIONS: In 1960, Nicotera inhabitants were following a diet defined as a "reference Italian Mediterranean diet", but by 1996 the Nicotera diet approached that of an average Italian diet, whose characteristics fall short of a true Mediterranean diet. This change in dietary habits may be responsible for an increased risk of CHD and cancer in the general population in the absence of other factors.

Adult↗
PubMed2000

Effect of increasing dose of interferon on the evolution of hepatitis C virus 1b quasispecies.

The effects of interferon therapy on hepatitis C virus (HCV) genome are still controversial in terms of biological and clinical significance. Changes in the quasispecies of the hypervariable (HVR) and non-structural 5A (NS5A) regions of HCV 1b were evaluated in nine patients treated with increasing doses of interferon and five untreated controls. HCV quasispecies were analyzed in HVR and NS5A by single-strand conformation polymorphism assay. The HVR quasispecies varied over time both in treated and untreated patients. However, at least one persistent strain was present in all patients. With low doses of interferon, variations in HVR complexity were found in seven of nine patients and in four patients new variants became detectable. A reduction in the heterogeneity of the HVR quasispecies was observed after increase of the interferon dose. In contrast, NS5A profiles remained unmodified in all but three cases in which direct sequencing showed no changes in amino acid sequences of the predominant strain. The results suggest that interferon sensitivity of some HCV strains may be dose dependent. The homogeneity of NS5A pattern populations during treatment suggests that interferon exerts much less pressure on this region.

5' Untranslated Regions↗
PubMed2000

Current awareness on yeast.

In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (4 weeks journals - search completed 16th Feb 2000)

Yeasts↗
PubMed2000

Cloning and characterization of the lactate-specific inducible gene KlCYB2, encoding the cytochrome b(2) of Kluyveromyces lactis.

In yeast the utilization of lactate requires two enzymes, the D and L-lactate ferricytochrome c oxidoreductase (D and L-LCR), which stereospecifically oxidize D- and L-lactate to pyruvate. These enzymes are nuclearly encoded and localized in mitochondria. In the yeast Kluyveromyces lactis, a mutant devoid of D- and L-LCR activities and unable to grow on racemic lactate was isolated. Transformation of the mutant with a K. lactis genomic library allowed the isolation of the KlCYB2 gene, restoring the growth on lactate and the L-LCR activity. The KlCYB2 gene and its flanking regions were sequenced (Accession No. AJ243324; EMBL/GenBank databases). The deduced amino acid sequence is highly homologous to the corresponding Saccharomyces cerevisiae and Hansenula anomala protein sequences previously characterized. The homology is missed in the N-terminal region, corresponding to the presequence cleaved during import into mitochondria. Analysis of KlCYB2 gene expression indicated that, in contrast to S. cerevisiae, the major regulatory feature is induction by lactate.

Amino Acid Sequence↗
PubMed2000

Clinical Experience with the NIR Stent: Retrospective Observation on Acute Results and Follow-up in 709 Patients.

The NIR stent is an expandable cellular coronary prosthesis with high flexibility and excellent trackability. The very low crossing profile, associated to the high flexibility, makes this stent suitable for complex and distal lesions. The aim of this study was to evaluate the feasibility, safety, and long-term (clinical follow-up) efficacy of elective and/or urgent deployment of the NIR stent in a broad patient group with coronary artery disease. Between June 1996 and May 1997, 986 NIR stents were implanted in 781 vessels (de novo or restenotic lesions in native vessels, saphenous vein grafts and internal mammary conduits) of 709 consecutive patients (498 men, 211 women) undergoing coronary angioplasty in two Villa Maria Group Catheterization Laboratories. Procedural angiographic success was achieved in 98.4% of all the lesions treated, ranging from 100% success rate in type A lesion to 97.6% in type C lesions (overall procedural success, 98.4%). Major adverse cardiac events (MACE) were considered from PTCA/stenting time to the patient discharge. The in-hospital MACE were limited and occurred in 15 patients: urgent surgical revascularization 0.8%, death 0.7%, sub-acute stent thrombosis 0.5% (overall in-hospital MACE rate 2.1%). Clinical follow-up data were obtained at 8.6 +/- 2.8 months following the stenting procedure. The event-free survival rate was 87.9%. The late MACE rate evaluation showed death, target lesion revascularization 9.9% (over-all late MACE rate 12.1%). The NIR stent performances in this broad patient population were excellent, showing very high procedural success rate both in normal and complex coronary anatomy. On the basis of the previous data, we can define NIR stent a safe multifunctional device suitable both for easy and complex situations. The clinical late results are very promising in term of event-free survivals and late MACE.

Journal Article↗
PubMed2000

Incidence and clinical characteristics of posttransplant lymphoproliferative disorders: report from a single center.

In the period 1973-1998, among 2139 allograft recipients treated with standard immunosuppression, posttransplant lymphoproliferative disorders (PTLD) developed in 19 patients (0.9%): one plasmacytic hyperplasia, two polymorphic PTLD, one myeloma, and 15 lymphomas. PTLD developed 1 year after transplantation (tx) in 14 patients. Five patients were diagnosed at autopsy, 2 were lost to follow up, 3 died before therapy could be instituted, and 1 patient has just started chemotherapy. Of the 8 evaluable patients, 2 received acyclovir and are alive in complete remission (CR) and 6 received chemotherapy +/- surgery. Of these 6, 4 died of lymphoma and/or infection, 1 died of unrelated causes in CR, and 1 is alive in CR. PTLD is a severe complication of tx, usually running an aggressive course which may preclude prompt diagnosis and treatment. Nevertheless, therapy is feasible and must be tailored on the histologic subtype. Seventy-four percent of patients were diagnosed with late-onset PTLD stressing the need for long-term follow up.

Acyclovir↗
PubMed2000

Incorrect echocardiographic diagnosis in patients with mechanical prosthetic valve dysfunction: correlation with surgical findings.

PURPOSE: To identify the rate of occurrence and type of incorrect echocardiographic diagnoses in patients with mechanical valve prostheses. PATIENTS AND METHODS: We studied 170 consecutive patients (73 women and 97 men) with a total of 208 prostheses who underwent surgery for mitral (n = 136) or aortic (n = 72) valve dysfunction between January 1991 and December 1997. Preoperative echocardiographic data were compared with surgical findings. Any major discrepancy between the echocardiographic reports and surgery was judged to be unconfirmed when the preoperative echocardiographic diagnosis was not confirmed at surgery, but the prosthesis was found to be dysfunctioning; and was judged to be erroneous when the preoperative echocardiographic diagnosis was not confirmed, and surgical inspection failed to reveal any other prosthetic abnormality. RESULTS: There were 25 (12%) diagnostic errors. Of the 136 mitral prostheses, there were 9 unconfirmed diagnoses of paravalvular regurgitation (6 had a fibrous tissue overgrowth, 1 had a thrombus with fibrous tissue overgrowth, 1 had endocarditis vegetations, and 1 had a ball variance) and 5 erroneous diagnoses. Eleven diagnostic errors were made in the 72 aortic prostheses: there were 9 unconfirmed diagnoses (paravalvular regurgitation was diagnosed as transvalvular in 7, and transvalvular regurgitation as paravalvular in 2 cases), and 2 erroneous diagnoses. CONCLUSIONS: Although echocardiography has gained great credibility among clinicians, special care should be taken when assessing patients in whom prosthetic valve dysfunction is suspected.

Aged↗
PubMed2000

An accessory open reading frame (orf-x) of jaagsiekte sheep retrovirus is conserved between different virus isolates.

Jaagsiekte sheep retrovirus (JSRV) is the etiological agent of a contagious lung tumour of sheep known as sheep pulmonary adenomatosis (syn: ovine pulmonary carcinoma, jaagsiekte). JSRV exhibits a simple genetic organization, characteristic of the type D and type B retroviruses, with the canonical retroviral sequences gag, pro, pol and env encoding the structural proteins of the virion. An additional open reading frame (orf-x), of approximately 500 bp overlapping pol, is present in the only two complete sequences of JSRV published to date. Since very little information is available on the biology of JSRV it is important to establish if orf-x is conserved between different virus isolates. In this study we analysed the orf-x region of JSRV isolates collected from the United Kingdom, Italy, Spain and South Africa. In addition we also analysed the presence of orf-x in JSRV-related endogenous sequences (enJSRVs) present in the sheep genome. Orf-x was highly conserved in all the exogenous isolates (n=10) and in most of the endogenous sequences (n=8). Thus orf-x may be an accessory gene of JSRV and haves a biological function which might be advantageous to JSRV. Phenetic analysis conducted on the complete orf-x nucleotide sequences seems to highlight the presence of three distinct groups statistically well supported by bootstrapping: i) exogenous JSRV sequence from the UK; ii) exogenous JSRV sequences from Southern Europe and iii) the exogenous South African strain plus all the endogenous sequences analyzed and collected from Australia, Italy, UK and South Africa.

Animals↗
PubMed2000

The pattern of response to interferon alpha (alpha-IFN) predicts sustained response to a 6-month alpha-IFN and ribavirin retreatment for chronic hepatitis C. TVVH Study Group.

BACKGROUND/AIMS: In chronic hepatitis C, interferon-alpha (alpha-IFN) and ribavirin combination therapy improves sustained response compared to alpha-IFN monotherapy, both in naive patients and in previous alpha-IFN relapsers, but the efficacy of such therapy remains limited in non-responder cases. The aim of this study was to assess whether the pattern of response to alpha-IFN alone may predict sustained response to combination therapy during retreatment. METHODS: Fifty previous alpha-IFN relapsers and 50 previous alpha-IFN non-responders were retreated with a high alpha-IFN dose (6 MU/thrice weekly for 2 months; induction phase) and then randomised to continue with alpha-IFN alone (3 MU/thrice weekly) or to receive combination therapy (3 MU/thrice weekly of alpha-IFN and 1000-1200 mg/daily of ribavirin) for an additional 6 months according to the biochemical response to alpha-IFN shown after the induction phase. All patients were also evaluated for virological and histological response. RESULTS: Eleven of 25 (44%) relapsers treated with combination therapy and 4/25 (16%) treated with alpha-IFN alone achieved a sustained response. The corresponding figures among non-responders were 1/25 (4%) and 0/25, respectively. Among 26 patients with a complete ALT and HCV-RNA response after 2 months of alpha-IFN, sustained response was seen in 11/14 (79%) treated with combination therapy and in 4/12 (33%) treated with alpha-IFN alone (p=0.05). On the other hand, of 74 cases still HCV-RNA positive after 2 months of alpha-IFN alone, biochemical and virological end of therapy response was better with combination therapy (11/36; 30.5%) compared to alpha-IFN alone (4/38; 10.5%), but only one patient developed a sustained response (1/36; 3%). CONCLUSIONS: The retreatment with a 6-month combination therapy was associated with a high rate of sustained response only in patients showing a complete biochemical and virological response to alpha-IFN alone. Longer retreatment with combination therapy may be needed to achieve a sustained response in patients without a prompt virological response to alpha-IFN.

Adult↗
PubMed2000

Comparison between three quantitative assays in patients with chronic hepatitis C and their relevance in the prediction of response to therapy.

To compare three quantitative assays measuring viral load in patients with chronic hepatitis C and to determine their value in predicting response to interferon (IFN) therapy, we analysed serum from 896 patients from eight European Centres using QUANTIPLEXtrade mark bDNA, MONITOR AMPLICORtrade mark and SUPERQUANTtrade mark assays. Analyses were performed on the same sample. Viral genotype was assessed using INNO-LiPA HCV II kits. Intercentre variations were observed that were related to the handling of specimens not processed and stored within 6 h of blood sampling. Among sera with optimal handling, a stronger correlation was observed between bDNA and SUPERQUANT (0.806) than between bDNA and MONITOR (0.677) and between MONITOR and SUPERQUANT (0.632). These discrepancies were greatest with genotype 2 (bDNA/SUPERQUANT= 0.772; bDNA/MONITOR=0. 456; SUPERQUANT/MONITOR= 0.299). This correlation was influenced by viraemia level and was better at lower viral loads. The proportion of sera with undetectable viral load was 15% with bDNA, 9.7% with MONITOR and 7.7% with SUPERQUANT. For the three measurements, the best cut-offs of sustained response to IFN treatment were located at their detection threshold. Among patients with viral load below the detection level, a sustained response was observed in 35% tested with bDNA, 38% with MONITOR and 80% with SUPERQUANT. Hence a stronger correlation was observed between bDNA and SUPERQUANT than between either of these assays and MONITOR. SUPERQUANT was the most sensitive assay and this greater sensitivity was associated with a better predictive value of treatment response.

Antiviral Agents↗
PubMed2000

Nitric oxide metabolites, prostaglandins and trigeminal vasoactive peptides in internal jugular vein blood during spontaneous migraine attacks.

Despite evidence emerging from the experimental model of nitroglycerin-induced headache, the endogenous increase in nitric oxide (NO) production during migraine attacks is only speculative. It has been hypothesized that there is a close relationship between activation of the L-arginine/NO pathway and production of certain vasoactive and algogenic prostaglandins during spontaneous migraine attacks, but this suggestion also needs to be confirmed. In the present study the levels of nitrites, the stable metabolites of NO, were determined with high performance liquid chromatography (HPLC) in the internal jugular venous blood of five patients affected by migraine without aura examined ictally. These samples were taken within 30 min, 1, 2, and 4 h from the onset of the attack and at the end of the ictal period. At the same time, the plasma levels of calcitonin gene-related peptide (CGRP), neurokinin A (NKA), prostaglandin E2 (PGE2) and 6 keto PGF1alpha, the stable product of PGI2, were assessed with radioimmunoassay (RIA) kits in the same samples. The levels of the intracellular messengers, cGMP and cAMP, were also measured with the RIA method. Nitrite, cGMP, CGRP and NKA levels reached their highest values at the first hour, then they tended to decrease progressively and returned, after the end of attacks, to values similar or below those detected at the time of catheter insertion (ANOVA, statistical significance: P<0.001; P<<0.002; P<0.002; P<0.003, respectively). PGE2 and 6 keto PGF1alpha, as well as cAMP levels also significantly increased at the first hour but reached a peak at the 2nd hour and remained in the same range until the 4th and 6th hours. Then their values tended to decrease after the end of attacks, becoming lower than those measured immediately after catheter positioning for internal jugular venous blood drawing (ANOVA: P<0.002, P<0.004, P<0.001, respectively). Our results support early activation of the L-arginine/NO pathway which accompanies the release of vasoactive peptides from trigeminal endings and a late rise in the synthesis of prostanoids with algogenic and vasoactive properties which may intervene in maintaining the headache phase.

Adult↗