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Biomedical subjects

C Perrotta

Publications and source records attributed to C Perrotta.

At least 19 recordsLinked to original sources

Description of controlled trials published in Methods and Findings, 1979-2002.

It is thought that the controlled trial (CT) is the most adequate research method to assess a therapeutic intervention in terms of efficacy, and it also constitutes the basis for the development of systematic reviews on health interventions. To identify and obtain the majority of published CTs is not an easy task, mainly because of limitations concerning the currently available electronic sources. The aim of the present work was to identify, describe, and assess the quality of CTs published in the journal Methods and Findings in Experimental and Clinical Pharmacology (M&F). Additionally, to assess the retrievability of both methods, a search was performed in Medline (PubMed access) through the use of an optimal search strategy for CTs. A total of 189 original studies out of a total of 2796 reviewed articles met the CT criteria according to the Jadad scale score, we could hold that only 58% of the CTs were of good quality. The present work confirms, once again, the limitations of a CT search performed exclusively through Medline (sensitivity 64% and specificity 98%). In conclusion, we suggest that the journal M&F explicitly joins the International CONSORT Statement.

Clinical Trials, Phase III as Topic↗

Chest physiotherapy for acute bronchiolitis in paediatric patients between 0 and 24 months old.

BACKGROUND: Acute bronchiolitis is the leading causes of medical emergencies during winter in children younger than two years of age. Chest physiotherapy is thought to assist infants in the clearance of secretions and decrease ventilatory effort. OBJECTIVES: To determine the efficacy and safety of chest physiotherapy in infants aged less than 24 months old with acute bronchiolitis. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2004) which contains the Acute Respiratory Infection Group's specialised register; MEDLINE (January 1966 to June 2004); EMBASE (1990 to June 2004); PASCAL; SCISEARCH; LILACS; and Cumulative Index to the Nursing & Allied Health Literature (CINAHL) (1982 to May 2004). SELECTION CRITERIA: Randomised controlled trails (RCTs) in paediatric patients younger than twenty four months old in which chest physiotherapy was compared against no intervention or against another type of physiotherapy. DATA COLLECTION AND ANALYSIS: Two independent reviewers extracted the data. Primary outcome was a severity clinical score. Secondary outcomes were length of hospital stay, duration of oxygen supplementation, and the use of bronchodilators and steroids. MAIN RESULTS: Three clinical trials met the inclusion criteria. All evaluated vibration and percussion techniques in postural drainage positions compared to no intervention. The study population were hospitalised infants with a clinical diagnosis of acute bronchiolitis, although one study included only infants who required nasogastric tube feeding or intravenous fluids. None of the other included trails observed any differences in the severity of the clinical score at day five or during each of the five days of the trial or until discharge, length of hospital stay, or oxygen requirements between chest physiotherapy group and control. AUTHORS' CONCLUSIONS: Based on the results of three RCTs, chest physiotherapy using vibration and percussion techniques does not reduce length of hospital stay, oxygen requirements, or improve the severity clinical score in infants with acute bronchiolitis that are not under mechanical ventilation, and who do not have any other co-morbidity. Chest physiotherapy using forced expiratory technique needs to be evaluated by clinical research.

Acute Disease↗

Cloning and characterization of the hsp 18.55 gene, a new member of the small heat shock gene family isolated from wine Lactobacillus plantarum.

Using a molecular approach based on PCR, RT-PCR and northern blot analysis, a new member of the small heat shock family of wine, Lactobacillus plantarum, was cloned and characterized. The protein sequence deduced from the isolated gene had a calculated molecular mass of 18.548 kDa and was therefore named HSP 18.55. The gene codes for a protein homologous to the previously characterized HSP 19.3 and HSP 18.5 and is co-transcribed with an upstream gene of unknown function. Analysis of the 5' flanking region of the hsp 18.55 gene revealed the presence of putative cis elements able to bind alternative sigma factor sigma(B). Based on its structure, the gene was classified as belonging to class II of the heat shock genes according to Bacillus subtilis nomenclature for shock-responsive genes. Expression of the newly identified small heat shock gene, analyzed by RT-PCR and northern blot analysis, was induced by a wide range of abiotic stresses including heat, cold and ethanol, suggesting that the small family of heat shock genes is probably involved in the general stress response in wine L. plantarum. Moreover, the expression of hsp 18.5, hsp 18.55 and hsp 19.3 genes, analyzed over a complete culture cycle, revealed that early growing cells contained substantial amounts of hsp 18.5, hsp 18.55 and hsp 19.3 mRNAs, which rapidly declined upon entry into stationary phase.

Amino Acid Sequence↗

Physiological characterization of 'stay green' mutants in durum wheat.

Four mutants with delayed leaf senescence were selected from seed of durum wheat mutagenized with ethylmethane sulphonate. Changes in net photosynthetic rate, efficiency of photosystem II and chlorophyll concentration during the maturation and senescence of the flag leaves of both mutant and parental plants were determined under glasshouse conditions. The four mutant lines maintained photosynthetic competence for longer than the parental line and are therefore functionally 'stay green'. The mutant lines also had higher seed weights and grain yields per plant than the parental line.

Apoptosis↗

Cyclic GMP-dependent inhibition of acid sphingomyelinase by nitric oxide: an early step in protection against apoptosis.

Activation of acid and neutral sphingomyelinases, and the ensuing generation of ceramide, contributes to the biological effects of tumour necrosis factor-alpha (TNF-alpha), one of which is apoptosis. While the mechanisms of activation of sphingomyelinases by the cytokine are being unravelled, less is known about regulation of their activity. Nitric oxide has previously been shown to exert a cyclic GMP-dependent inhibition of early apoptotic events triggered by TNF-alpha in the U937 monocytic cell line. We therefore investigated whether inhibition of sphingomyelinases by nitric oxide plays a role in regulating such early events. We found that activation of both acid and neutral sphingomyelinases, triggered in the first minutes after U937 cell stimulation with TNF-alpha, is regulated in an inhibitory fashion by nitric oxide, working through generation of cyclic GMP and activation of protein kinase G. Using a range of inhibitors selective for either sphingomyelinase we found that the acid sphingomyelinase contributes to activation of the initiator caspase-8 and early DNA fragmentation and that inhibition of the acid enzyme by nitric oxide accounts for cyclic GMP-dependent early protection from apoptosis. We also found that the protective effect by both cGMP and acid sphingomyelinase inhibitors progressively disappeared at later stages of the apoptotic process. Inhibition of sphingomyelinases represents a novel action of nitric oxide, which might be of physiological relevance in regulating initial phases of apoptosis as well as other biological actions of ceramide.

Apoptosis↗

[A case of familial Bardet-Biedl syndrome (obesity, slight mental retardation, polydactyly, retinitis pigmentosum and renal failure) with insulin-resistant diabetes mellitus].

A case of familial Bardet-Biedl syndrome (BBS) in a 64-year-old woman is presented; it is characterized by abdominal obesity (BMI: 38.28; WHR: 0.98), slight mental retardation, polydactyly, pigmentary retinopathy and moderate renal failure, with insulin-resistant diabetes mellitus and severe inflammation of the left limb with necrosis of the last toe (the sixth) of the left foot. Four brothers and sisters of the patient presented the same syndrome. The patient had had healthy offsprings. The review of current literature indicates that BBS is a genetic autosomal recessive disease, formerly grouped with Laurence-Moon-Biedl syndrome but today considered as a separate entity. It is characterized by obesity, mental retardation, dysphormic extremities (syndactyly, brachydactyly or polydactyly), retinal dystrophy or pigmentary retinopathy, hypogonadism in males, and renal structural abnormalities or functional impairment. Extra- and intrafamilial variability of expressivity and severity of the various clinical manifestations was reported, among affected families and also in the same family. BBS is a rare but important syndrome, that should be known by the endocrinologist and the specialist in internal medicine, because it has an adverse prognosis, with early onset of blindness, insulin-resistant diabetes mellitus and severe renal impairment. Renal failure is a frequent cause of death early in life, even in the infant-juvenile years.

Diabetes Mellitus, Type 1↗

Identification, characterization, and analysis of cDNA and genomic sequences encoding two different small heat shock proteins in Hordeum vulgare.

In vitro translation of mRNAs prepared from barley (Hordeum vulgare) seedlings (cv. Onice) exposed at 40 degrees C directed the synthesis of major heat shock proteins (HSPs) with molecular masses of 80-90, 70, 42 and 16-22 kDa. A cDNA library prepared from the 40 degrees C mRNAs and screened by differential hybridization led to the isolation of heat shock specific sequences. One of these (Hv hsp18) was confirmed by hybrid-arrested and hybrid-released translation as encoding for an 18-kDa HSP. The barley hsp18 sequence has an open reading frame encoding a 160 amino acid residue 18-kDa protein that is 63% identical to wheat 16.9-kDa HSP (clone C5-8), 54% identical to soybean (Glycine max) 17.5-kDa HSP, and 49% identical to Arabidopsis thaliana 17.6-kDa HSP. Lower similarities were found with class II plant small HSPs such as soybean 17.9-kDa HSP (27%), Pisum sativum 17.7-kDa HSP (30%), wheat (Triticum aestivum) 17.3-kDa HSP (clone Ta hsp 17.3) (30%), and with animal small HSPs and alpha-crystallins. The Hv hsp18 sequence was used to pick up Hv hsp17 genomic sequence encoding for another class I 17-kDa HSP. By computer analysis of the nucleotide sequence the TATA box, two heat shock promoter elements, a metal-ion response element, and the polyadenylation signals were identified. Barley HSP18 has an additional cysteine-rich region when compared with HSP17 mapping at the carboxy terminal end.

Amino Acid Sequence↗

Ventricle-to-brain ratio and symptoms at the onset of first-break schizophrenia.

Ventricle-to-brain ratio (VBR) was measured from the computed tomographic (CT) scans of 33 very recent-onset psychotic patients. Illness severity and positive and negative symptoms were also assessed in 21 of these patients with schizophreniform disorder. Forty-five neurology patients served as controls. Analyses revealed no significant differences between the VBR of the psychotic group as a whole, the schizophreniform subgroup, the affective psychotic subgroup, and the controls. Control subjects with a neurological diagnosis of vertigo or syncope had significantly higher VBR than the remainder of the control group and the psychotic group. When the psychotic group was compared to the control group minus those controls with syncope or vertigo, the psychotic group had significantly higher VBR. The schizophreniform subgroup also had significantly higher VBR than the control group minus subjects with vertigo or syncope. In the schizophreniform subgroup, positive symptoms and illness severity were associated with smaller VBR. There was no association between negative symptoms and VBR.

Adolescent↗

c-myc oncogene alterations in human thyroid carcinomas.

A possible role of the c-myc oncogene in the neoplastic transformation of the human thyroid has been investigated. The structure, the methylation status, and the copy number of this oncogene have been analyzed in normal and in tumor thyroid DNAs by Southern blotting technique and dot blot hybridization. Among six carcinomas, four presented abnormal c-myc DNA structure: Three cases showed a mutation in the 5' flanking region of the gene, originating a new EcoRI site; the other case showed a deletion of 5 kb involving the first exon of the gene. This deletion was also observed in the white blood cells of the same individual. In addition, in three carcinomas a double dose of the oncogene has been demonstrated. In all the carcinomas examined, undermethylation of the c-myc oncogene has been observed. These findings suggest that c-myc oncogene alterations might be involved in the malignant transformation of the human thyroids and can be considered as tumor markers.

Base Sequence↗

beta (+)-Thalassaemia in the Po river delta region (northern Italy): genotype and beta globin synthesis.

Six beta(+)-thalassaemic patients from the Po river delta region have been studied. Using synthetic oligonucleotides as specific hybridisation probes, the beta(+) IVS I mutation (G----A at position 108) was demonstrated. This lesion and the enzyme polymorphism pattern in the subjects examined are the same as have been described for other Mediterranean beta(+)-thalassaemias. Antenatal diagnosis through DNA analysis of beta(+)-thalassaemia is therefore possible. The production of beta globin in a beta(+), homozygote and in a beta (+), beta(0) 39 (nonsense mutation at codon 39) double heterozygote is approximately 20% and 10% respectively of total non-alpha globin synthesis. Despite some overlapping of the results, similar beta globin synthesis levels have been obtained in 43 beta(+)-thalassaemia patients. This suggests that in the Po river delta region the most common thalassaemic genes are beta(0) 39 and beta(+) IVS I.

Autoradiography↗

[Construction of a genome library from a beta-0-thalassemic individual from Ferrara: characterization of clones containing beta globin genes].

A library of genomic DNA was prepared from a patient with beta o Ferrara thalassaemia: random human DNA fragments (15 - 20 Kb) have been joined to phage lambda vectors and cloned has viable phage particles (4). 4x10(5) phages have been screened for their content in beta globin gene sequences, using a human beta cDNA plasmid (5) as hybridization probe. Five positive clones have been isolated and characterized by restriction endonuclease cleavage analysis and by the hybridization experiments. The results obtained allow the precise localization of the human fragments inside the beta like globin gene cluster (6). The comparison of the thalassaemic fragments with the normal DNA (6 - 7) shows two different restriction endonuclease sites, for Xba I and Eco RI respectively, downstream from the human beta globin gene.

Cloning, Molecular↗

Molecular characteristics of a non-deletion alpha-thalassaemia of the Po River Delta.

The form of alpha-thalassaemia of the Po river delta presents haematological and globin biosynthetic characteristics similar to alpha-thalassaemia-1 but never gives rise to HB H disease nor to hydrops foetalis. In alpha-thalassaemic subjects originally from this region globin mRNA translation and alpha-globin gene arrangement have been investigated. The data obtained indicate that alpha-globin synthesis and reticulocyte alpha-globin mRNA are reduced by one fourth; in addition, since the defect in alpha-globin synthesis does not change with cell ageing, a possible instability of alpha-globin mRNA is excluded. Restriction enzyme analysis of the DNA shows a normal alpha-globin gene organization. This form of alpha-thalassaemia is therefore of the non-deletion type; its molecular lesion is either at the level of alpha-globin mRNA transcription or processing. The fact that this, as well as other forms of non-deletion alpha-thalassaemia, have a phenotypic expression similar to alpha-thalassaemia 1 is discussed.

Genes↗

[Messenger RNA in cases of heterozygous beta and delta-beta Thalassemia. Biosynthetic and hybridization studies].

mRNA-cDNA hybridization, intact reticulocytes biosynthesis and heterologous cell-free translation studies have been performed in cases of heterozygous beta and delta beta thalassaemia. Results obtained have shown that the relative amount of beta mRNA is higher in Ferrara microcytes than in other heterozygous including delta beta. This indicates that transcription of beta globin gene takes place in Ferrara beta 0 thalassaemia. On the contrary globin biosynthesis studies have failed to show clear-cut differences among the various heterozygous considered and cannot evaluate the translatability of beta thal. FemRNA.

Cell-Free System↗

[Globin synthesis in erythroid cultures from normal and thalassemic subjects].

Relative alpha and beta chain synthesis in erythroid bursts derived from human bone marrow and peripheral blood are presented. The biosynthetic ratios obtained are compared with those of the reticulocytes. The data obtained cell culture are similar to the "in vivo" ones, showing and alpha/beta ratio of 1 in normal individuals and higher than 1 in beta thalassemic heterozygous. The use of erythroid cell culture as an experimental model for the study of differentiation at molecular level is therefore possible.

Bone Marrow Cells↗