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Biomedical subjects

A Muro

Publications and source records attributed to A Muro.

At least 37 records · Page 2Linked to original sources
PubMed1998

Altered calcium handling in compensated hypertrophied rat cardiomyocytes induced by pressure overload.

To investigate Ca2+ handling in compensated hypertrophied cardiomyocytes, we measured Ca2+ transients and contraction of hypertrophied rat left ventricular myocytes induced by aortic constriction (AC). The fluorescence ratio (I405/I480) after indo-1/AM loading and circumferential length were simultaneously measured in isolated myocytes. The amplitude of Ca2+ transients (Ca-Amp) was higher in rats with AC than in sham-operated rats (Sham) (0.25 +/- 0.08 vs 0.17 +/- 0.05). There was a positive correlation between Ca-Amp and fractional shortening (FS) in both AC and Sham rats, whereas the ratio of FS/Ca-Amp was smaller in AC rats. These observations suggest that compensated hypertrophied cardiomyocytes exhibit an adaptive increase in Ca-Amp, associated with reduced myofilament responsiveness to an increase in Ca2+. Isoproterenol and forskolin increased Ca-Amp and FS, and decreased time to 50% decline of Ca2+ transients. Although myocytes from AC rats exhibited reduced responsiveness to isoproterenol, responses to forskolin did not differ between the 2 groups. The reduced beta-adrenergic response in Ca2+ handling was probably due to altered beta-adrenoceptor numbers, G-protein function and/or their coupling process.

Adrenergic beta-Agonists↗
PubMed1997

Fasciola hepatica: vaccination of rabbits with native and recombinant antigens related to fatty acid binding proteins.

The current study was designed to compare the immunogenic and immunoprophylactic properties of native (nFh12) and recombinant (rFh15) antigens from Fasciola hepatica in rabbits infected with the fluke. Levels of specific anti-nFh12 and anti-rFh15 antibodies were significantly higher in the rabbits vaccinated twice compared with non-vaccinated infection controls. A reduction of 40% in worm burdens was found in rabbits immunized with nFh12 and infected 4 weeks after the second immunization. The recombinant vaccine induced lesser levels of protection than the native one, suggesting that both molecules may have slight differences either in immunogenicity or in their configuration. Further biochemical studies are required to define these differences. The mean length of flukes recovered was always smaller in all vaccinated rabbits. In addition, infected control rabbits had higher gamma glutamil transferase (GGT) levels than immunized rabbits. Lastly, gross anatomic observation always showed fewer liver lesions in all vaccinated rabbits than in controls. This finding clearly supports the possibility of vaccination regimes in fasciolosis.

Animals↗
PubMed1997

A preliminary assessment of the recombinant antigen PLA2 in the diagnosis of human dirofilariosis.

Two recombinant antigens (P22U and PLA2), cloned in a L4 Dirofilaria immitis cDNA library, were analyzed by Western-blot and ELISA to investigate their characteristics for the diagnosis of human dirofilariosis. P22U seems related to a Di22 native antigen useful for the diagnosis of pulmonary dirofilariosis, but it is unspecifically recognized by sera from patients with different parasitic and non parasitic pulmonary diseases. PLA2 is not related to Di22 but specifically reacts in Western-Blot and ELISA with sera from patients with subcutaneous dirofilariosis.

Antigens, Helminth↗
PubMed1997

[Mucin-hypersecretory pancreatic tumors: a pathology with defined characteristics].

We report a case of a mucin-producing tumor of the pancreas, a rare neoplasm of which only a few cases have been described in Europe. The finding of progressive hyperamylasemia without abdominal pain suggests the presence of this type of tumor. At endoscopic retrograde cholangio-pancreatography (ERCP), mucinous excretion and ductal dilation were found. Its prognosis is better than adenocarcinoma.

Adenocarcinoma, Mucinous↗
PubMed1997

Human humoral immune response to Dirofilaria species.

Dirofilaria immitis and D. repens, the agents of human pulmonary and subcutaneous dirofilariosis respectively, may coexist in areas of Southern Europe, and L3 and L4 of both species develop in subcutaneous tissue. Previous studies have shown that humans develop high levels of specific IgM, IgG and IgE anti-D. immitis. An antigen of approximately 22 kDa (Di22) is a marker of pulmonary dirofilariosis. In this work, we demonstrate that D. repens also induces IgG in infected humans. Polypeptides between 40 and 26 kDa from adult somatic antigenic complex of the later species, are specifically recognized by sera from individuals with subcutaneous dirofilariosis due to D. repens. These findings complement the previous studies on specific antigens for the serological diagnosis of pulmonary dirofilariosis.

Animals↗
PubMed1996

Extrahepatic bile duct carcinoma: US characteristics and accuracy in demonstration of tumors.

PURPOSE: To assess the accuracy of ultrasonography (US) in the demonstration of extrahepatic biliary tree cholangiocarcinoma and to analyze US features of the different morphologic types of this tumor. MATERIALS AND METHODS: US findings were reviewed retrospectively in 49 patients with pathologically proved cholangiocarcinoma. Findings from percutaneous transhepatic cholangiography (n = 47) and endoscopic retrograde cholangiopancreatography (ERCP) (n = 2) were compared with those from US. RESULTS: US demonstrated the tumor in 47 (96%) of the 49 patients; a mass was demonstrated in 44 patients, and a focal or diffuse thickening of the bile duct wall was seen in three patients. CONCLUSION: The accuracy of US in depicting cholangiocarcinoma was attributable to the skill of the radiologists who performed the study and evaluated the findings and to the high frequency of tumor at the hilar level, where the liver and gallbladder allowed a clear acoustic window that facilitated detection of tumors.

Adult↗
PubMed1995

Genomic organisation and chromosomal localisation of the gene encoding human beta adducin.

Adducin (ADD) is a heterodimeric protein of the membrane skeleton with subunits of 103 (alpha) and 97 kDa (beta). It promotes the assembly of the spectrin-actin network. We have previously shown that one point mutation in each of the alpha and beta rat ADD-encoding genes is associated with blood pressure variation in an animal model for hypertension, the Milan hypertensive strain of rats, probably due to a change in the phosphorylation pattern. In fact, the rat mutations, Y to F for alpha and R to Q for beta, are located, respectively, in a tyrosine kinase and a protein kinase A phosphorylation site. We have now determined, for the human beta-ADD-encoding gene, its chromosomal localisation, exon-intron organisation and alternative splicing patterns. We report here that human beta-ADD is localised on chromosome 2 and we also show a characteristic 3' end alternative splicing of the beta-ADD RNA that generates two distinct beta-ADD families, namely ADD 63 and 97; both of them in turn present a very complex differential splicing pattern in the internal exons.

Alternative Splicing↗
PubMed1995

Characterisation and chromosomal localisation of the rat alpha- and beta-adducin-encoding genes.

A polymorphism in the genes encoding alpha- and beta-adducin (ADD) was described as being associated with blood-pressure variation in a genetically hypertensive strain of rats (MHS). ADD is a cytoskeletal heterodimeric protein which may be involved in cellular signal transduction and interacts with other membrane skeleton proteins which affect ion transport across the cell membrane. The cDNA encoding the alpha subunit of rat ADD was isolated using PCR methods. The cDNA consists of about 3900 bp and encodes a protein of 735 amino acids (aa) which shows 91% aa identity with the human counterpart. In spleen and kidney, three alternative spliced exons were found by PCR amplification and confirmed by RNase protection analysis. 17 inbred rat strains were genotyped for the polymorphism in the alpha- and beta-ADD genes. Chromosomal localisation mapped rat alpha-ADD on chromosome 14 and rat beta-ADD on chromosome 4.

Alleles↗
PubMed1995

Evaluation of Dirofilaria immitis excretory/secretory products for seroepidemiological studies on human dirofilariosis.

The usefulness of excretory/secretory (E/S) products of adult Dirofilaria immitis for the diagnosis of human dirofilariosis was evaluated in 97 human sera using an ELISA and a Western Blot analysis with E/S antigens. Results of the ELISA analysis show that in healthy individuals from an endemic area seropositivity is high (22%). Immuno Blot analysis shows that the reaction pattern with E/S antigens differentiates healthy seropositives, which recognize a 43 kDa band, from patients with pulmonary dirofilariosis, which specifically recognize bands between 22-28 kDa.

Animals↗
PubMed1995

Serological diagnosis of subcutaneous dirofilariosis.

We present serological evidence that Dirofilaria immitis was the causative agent of subcutaneous nodules in two patients. ELISA and enzyme-linked immunoblot analysis showed that the two human sera had a reactivity pattern similar to that of D. immitis rabbit immune serum. The reaction pattern of the human sera was very different to that of Dirofilaria repens rabbit immune serum. In the light of our findings, the traditional view that subcutaneous filarial nodules are due to D. repens has to be revised.

Adult↗
PubMed1994

Identification of genes that encode Fasciola-specific arc 2 antigens.

Previous studies have shown that serum from humans with fascioliasis had precipitating antibodies that identified a line of precipitation as specific for Fasciola. This Fasciola-specific band was designated arc 2. The specificity of a Fasciola-specific anti-arc 2 antiserum, evaluated by Western blot analysis, reveals a mosaic of antigens with molecular weights in the range of 10-43 kD. In the current study, the antibodies reacting with a subset of antigens in the 10-21-kD range were eluted from nitrocellulose and used to probe an F. hepatica cDNA library. Four clones were purified and amplified by the polymerase chain reaction. The DNA hybridizations among these clones revealed different groups of clones derived from different mRNAs. The finding of multiple genes supports the observation that F. hepatica arc 2 is a mosaic of antigens. The studies show that molecular cloning technology can be used to identify potential genes, each of which encode distinct antigens that may be used for the specific immunodiagnosis of fascioliasis.

Animals↗
PubMed1994

Evaluation of a 22 kDa Dirofilaria immitis antigen for the immunodiagnosis of human pulmonary dirofilariosis.

Human pulmonary dirofilariosis usually appears as a solitary pulmonary nodule. A 22 kDa antigen from Dirofilaria immitis adult worms specifically recognized by three sera from individuals diagnosed with pulmonary dirofilariosis was identified by enzyme-linked-immunoelectrotransfer blot. This antigen was purified by elution from acrylamide gels and evaluated in enzyme-linked immunoassay using sera from 92 patients with pulmonary dirofilariosis and other pulmonary and parasitic diseases. Its use in the diagnosis of human pulmonary dirofilariosis should be considered.

Animals↗
PubMed1994

[Human dirofilariasis: identification of a 44kD antigen recognized by IgM against Dirofilaria immitis].

BACKGROUND: Dirofilaria immitis is a nematode parasite of canids that, in endemic areas, can infect humans. The use of adult somatic antigens for the diagnosis of human dirofilariasis has the disadvantage of a low sensibility because of cross-reactivity with other helminths, specially with IgM antibodies. We describe in this work proteins of the adult somatic antigenic complex that are specifically recognized by human IgM. METHODS: Human sera with different characteristics were analyzed by an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-D. immitis IgM seropositive individuals. Moreover, an enzyme-linked immuno-electro-transfer blot (EITB) was performed for the detection of polypeptides that specifically react with IgM anti-D. immitis. RESULTS: EITB analysis shows that 2 proteins of 44 and 18 kD are recognized by IgM in human sera from an endemic area with a high antibody titer against D. immitis measured by ELISA. Sera from a non-endemic area and from patients suffering from other parasitic and non-parasitic diseases did not recognize these antigens. CONCLUSIONS: We believe that the 44 kD protein could be a good marker of recent D. immitis infection.

Animals↗
PubMed1993

Sequence analysis of a Fasciola hepatica glutathione S-transferase cDNA clone.

A lambda gt11 Fasciola hepatica cDNA library was previously constructed from poly(A)+ RNA extracted from adult worms. A cDNA encoding F. hepatica glutathione S-transferase (FhGST) (GenBank Accession Number M93434) was cloned by screening the library with a rabbit anti-FhGST antiserum. The FhGSTs are suspected to be early developmentally expressed-proteins that act as potent immunogens and may be useful as candidate vaccines against the parasite. The cDNA was sequenced and contains 627 translated bases encoding a 24,211-Dalton polypeptide with 209 amino acids and an isoelectric point (pI) of 5.324. This polypeptide has significant homology with 26-kD GSTs from Schistosoma mansoni (57.42%) and S. japonicum (57.14%). In addition, we have identified the predicted T cell epitopes in the FhGST protein molecule.

Amino Acid Sequence↗
PubMed1993

Anti-Dirofilaria immitis IgE: seroepidemiology and seasonal variation in an exposed human population.

The seroprevalence of seasonal variation of human anti-Dirofilaria immitis IgE levels were studied in an area where specific IgM and IgG had been previously investigated. An antibody capture ELISA assay was used to detect specific IgE. The IgE seroprevalence observed in the whole population was 12.6%. No specific IgE was detected in atopic individuals or in sera from people suffering other helminthiases. The distribution of the IgE anti-D. immitis seroprevalence by age groups did not show differences. Females had significantly higher levels than males. This isotype of immunoglobulin peaks in July, decreasing sharply in October, and persisting at a level similar to that of a non exposed population during the rest of the year. No specific IgE were detected in subjects with pulmonary alterations related to the parasite, suggesting a possible relationship between the clinico-radiological status and the type of immunoglobulin synthesized in subjects infected by D. immitis.

Adult↗
PubMed1992

Are transient pulmonary solitary nodules a common event in human dirofilariosis?

Infection by Dirofilaria immitis is a rare cause of solitary pulmonary nodule. We describe the second case of transitory pulmonary nodule found by us in the course of a case-finding study, the third one reported in the literature. The detection of cases of transient pulmonary dirofilariotic nodules suggests that human infection is more prevalent than usually thought, and that this kind of manifestation is frequent in human dirofilariosis. Greater awareness is warranted in endemic areas.

Aged↗