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Biomedical subjects

A Marchi

Publications and source records attributed to A Marchi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Treatment of Romberg's disease with parascapular free flap and polyethylene porous implants.

Romberg's disease is a rare condition characterized by progressive hemifacial atrophy. The atrophic process typically has its onset in the first or second decade of life, it continues for a few years (usually 2, but up to 10), and then it stops spontaneously. The subcutaneous tissue is the first to be involved by the disease, followed by muscles, bones, and, rarely, the skin. The etiology of the disease is unknown. The only available treatment is surgical. Several techniques have been reported in the literature, from fat transplant, to silicon prostheses, to the use of flaps. We present our experience in successfully treating six patients (3 males and 3 females) affected by Romberg's hemifacial atrophy of intermediate or severe degree. A technique including a free parascapular microvascular flap with the adjunct of porous polyethylene implants was used. Further correction was performed with remodeling or resuspension.

Adipose Tissue↗
PubMed1998

Characterization of Toscana virus-defective interfering particles generated in vivo.

Toscana (TOS) virus stocks strongly interfering with standard virus replication were obtained by sequential passages of virus in suckling mouse brain. Characterization of viral RNAs in these stocks showed the presence of a heterogeneous population of defective RNA molecules derived from the L genomic segment, in both nucleocapsid (NC) and messenger RNAs, suggesting that these molecules could be replicated, assembled, and transcribed. Subgenomic RNAs from the L segment but not from the S or M segments were found in cells infected with these stocks. Defective RNA molecules interfered with virus replication and retained 5' and 3' genomic termini. Nucleotide sequence analysis of some cloned defective interfering (DI) RNAs revealed they contained one or more internal deletions reducing their length to 7-13% of the full-length L segment. An identical sequence motif, of variable length, was found at both terminal sites of the RNA junction on standard L sequences. This motif was retained only in one copy in the subgenomic RNA. These results are consistent with the generation of TOS virus DI particles in vivo and suggest that the defective genomic RNAs could be generated by polymerase jumping from a sequence to an identical one spatially closed because of the RNA structure.

Animals↗
PubMed1998

Response to long-term hGH therapy in two children with Schwachman-Diamond syndrome associated with GH deficiency.

Schwachman-Diamond syndrome is a rare congenital disorder characterized by pancreatic insufficiency, metaphyseal anomalies, recurrent infections, hematologic abnormalities, and growth retardation. Slow growth in these patients has been attributed to nutritional deficits, recurrent infections, and skeletal anomalies. Two cases of Schwachman-Diamond syndrome associated with growth hormone deficiency have been previously reported. We report here on 2 additional cases with this unusual association. Therefore, growth failure in Schwachman-Diamond syndrome should not be assumed to be due to chronic illness or recurrent infections; other etiologies for growth failure should be sought. However, the presence of metaphyseal disorders probably interferes with the long-term efficacy of growth hormone substitutive therapy.

Adolescent↗
PubMed1997

Refinements in microvascular repair of extended oromaxillofacial defects with radial forearm free flap.

The radial forearm free flap (RFFF) is one of the most widely used and versatile fasciocutaneous free flaps in head and neck reconstruction because of its qualities--the consistent vascular anatomy; the thin and pliable nature; the minimal hair presence; and the possibility of harvesting and transferring it as a composite tissue flap, with bone, tendon, and nerve. The RFFF provides a method of single-stage reconstruction of wide residual defects after excision of advanced cancer (T3-T4) in the head and neck region. We present our ten-year experience with RFFF and the good results obtained with some refinements, which allowed us to verify the efficacy of the oral competence using the palmaris gracilis tendon as a sling. We also present the possibility of harvesting long segments of radius (up to 18 cm), and the discovery that use of antithrombotic or anticoagulant therapy is not necessary for the flap survival. This treatment does not guarantee a complete recovery, but it can improve the quality of the patient's life.

Adult↗
PubMed1997

Status of malaria vectors in Italy.

About 30 yr after malaria eradication, surveys to assess the presence and abundance of anopheline vectors were carried out in central and southern Italy and in the islands of Sardinia and Sicily from 1992 to 1994. Anopheles labranchiae Falleroni was present in scattered foci in all regions, except for Tuscany, where it breeds almost exclusively in rice fields (Grosseto Province). Most common breeding sites were rivers and streams, followed by ponds and ground pools. The highest adult density was found in Tuscany near rice fields and along the west coast of Calabria. Anophelines in Grosseto were abundant at human bait, with peaks of > 200 landings per human per night and vectorial capacity between 7.3 and 26 for Plasmodium falciparum and between 8.3 and 32.5 for Plasmodium vivax. Anopheles sacharovi Favre, a former malaria vector in Puglia and Sardinia, was not found in these regions. The other vector in southern Italy, Anopheles superpictus Grassi, was found at low densities on the western and eastern coasts of Calabria. All anopheline populations were fully susceptible to deltamethrin, malathion, and DDT but showed reduced susceptibility to permethrin and propoxur. These data are discussed in the light of a possible reintroduction of malaria into Italy.

Animals↗
PubMed1997

A variant of the Nijmegen breakage syndrome with unusual cytogenetic features and intermediate cellular radiosensitivity.

We report the first Italian case of Nijmegen breakage syndrome (NBS). The proband is an immunodeficient, microcephalic, 11 year old boy with a "bird-like" face. He developed a T cell rich B cell lymphoma. Spontaneous chromosomal instability was detected in T and B lymphocytes and fibroblasts; chromosomes 7 and 14 were only sporadically involved in the rearrangements and no clonal abnormality was present. The patient appeared to be sensitive both to ionising radiation and to bleomycin, although his sensitivity did not reach the level of AT reference cells. After bleomycin treatment, inhibition of DNA synthesis was low when compared with normal cells, but higher than observed in an AT reference strain. Moreover, cell cycle analysis, after drug exposure, showed a progressive reduction in the percentage of S phase cells, but the G1 arrest, found in normal cells, was not observed. On clinical evaluation our patient shares features with NBS subjects, but cytogenetic and cell biological data do not completely overlap with those reported in Nijmegen breakage syndrome. The ethnic origin of our patient might account for these differences, as expression of different allelic forms at the NBS locus.

Antigens, Surface↗
PubMed1995

[Amalgam and the toxicological risks of mercury. A review of the argument].

The employment of dental amalgam in the area of conservative dentistry, in spite of representing an excellent therapeutic solution, is today undergoing criticism more frequently than before because of the potential toxicity of mercury regarding hyman health and environmental salubrity. Mercury is a metal having the tendency to evaporate at ambient temperature and it is just the inhalation of its vapor the most common form of exposure to mercury for man. The absorption may also may also occur through food ingestion or accidental swallowing of metal particles coming from dental amalgam fillings. Mercury poisoning usually turns out to be a chronic process which causes its major toxic effects at the expense of digestive, excretory and neurocentral apparatuses. Several authors have studied mercury exposure on the working places, including in their investigation persons operating in the dentistry departments: they found high levels of mercury existing both in tissues and in biological fluids in people affected by exposure, frequently accompanied by symptoms of chronic intoxication. More recent studies, however, do not fully confirm such conclusions and exclude that coming into contact with mercury vapor on the working place may be in connection with an increase of mortality. Exposure to mercury from amalgam for the most part occurs through ingestion of amalgam particles abraded from restored surfaces, inhalation of vapors generated during dental restorative procedures and deglutition of saliva into which corrosion products have dissolved.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Late results of breast reconstruction with free TRAM flaps: a prospective multicentric study.

When the free TRAM flap was introduced for breast reconstruction, it was supposed to have many advantages over the pedicled TRAM flap: good perfusion of all four zones, better mobility and easier shaping of the breast, lower incidence of abdominal-wall complications, and less restrictive selection of patients. However, we have experienced several complications after free TRAM flaps in our practice, including fat necrosis, partial and complete flap necrosis, abdominal-wall weakness, and hernias. In order to evaluate the incidence and types of complications, as well as the influence of preoperative risk factors (chemotherapy, radiotherapy, overweight, smoking habits, and abdominal scars), on complications, a multicentric prospective study including Bern (Switzerland), Leuven (Belgium), Stuttgart (Germany), and Verona (Italy) was designed. In 111 consecutive patients, operated on over a period of 18 months, 123 flaps were done; 99 flaps were unilateral and 24 bilateral, and 36 were used for primary and 87 for late reconstruction. There was no preoperative selection of patients. The follow-up period was from 8 to 24 months (average 19 months). A two-team operating approach was used. All four zones were always included in the flap, and the end-to-end anastomoses were done to the thoracodorsal, the circumflex scapular, or the internal mammary arteries. The total number of fat and flap necroses was 24 (19.5 percent), 6 (5 percent) minor and 4 (3 percent) major fat necroses, 2 (1.6 percent) minor and 6 (5 percent) major flap necroses, and 6 (5 percent) total flap necroses. Twenty-two (20 percent) patients had abdominal-wall complications. The results of this study show that the complication rate of free TRAM flaps is considerable. Preoperative risk factors did not play a major role in the development of complications and should not be considered as contraindications for free TRAM flap surgery. All total flap failures resulted from impaired arterial inflow to the flap, and the choice of recipient vessel did not influence the outcome. The incidence of total flap failures might be reduced by good postoperative flap monitoring and early revision of the anastomosis. Partial fat and flap necroses might be prevented by removing the fat under the scarpa fascia in zones 4 and 3 or by reducing zone 4. Sparingly harvesting the rectus muscle and its sheath as well as the use of mesh in the rectus sheath repair may reduce the abdominal-wall complications.

Breast Neoplasms↗
PubMed1994

Sustained remission of immune-mediated red cell aplasia in a child after intravenous administration of gamma globulin.

A 4-year-old white boy with immune-mediated red cell aplasia and severe anemia was given high intravenous doses of gamma-globulin. The therapy was well tolerated and followed by complete resolution of the inhibition of erythropoiesis with no recurrence of disease. Eight months after discontinuation of treatment, the patient has a normal complete blood cell count.

Bone Marrow↗
PubMed1994

Ribosomal RNA genes in mosquitoes: localization by fluorescence in situ hybridization (FISH).

Fluorescence in situ hybridization (FISH) was used to localize the 18S-28S ribosomal RNA gene clusters on the chromosomes of 15 mosquito species belonging to the Anophelinae and Culicinae subfamilies. In the genus Anopheles the rRNA genes are localized on the heterochromatic arm of both sex chromosomes. The association between rRNA genes and sex determining chromosomes also applies to the homomorphic karyotype of Culicinae mosquitoes, at least in those cases in which localization of the sex locus/loci has been determined. In these species ribosomal genes are often found within or adjacent to heterochromatic regions (C bands). Differences in the location of rRNA genes among and within genera suggest the occurrence of several chromosomal rearrangements during the evolution of mosquitoes.

Animals↗
PubMed1994

[Residual anophelism in Italy: distribution in 4 southern regions].

About 40 years after malaria eradication from Italy, the potential vectors of this disease, Anopheles labranchiae, Anopheles superpictus and Anopheles sacharovi, are still present in some regions of the South. Since 1991 the Laboratory of Parasitology, Istituto Superiore di Sanità, in collaboration with the Local Health Authorities, carried out an investigation to assess the levels of these potential anopheline vectors in Calabria, Puglia, Sicily and Sardinia. A. labranchiae, the most important vector, was found in all the regions visited, where is probably present in scattered foci all over the territory. The most common breeding sites were represented by rivers and streams, followed by ponds and ground pools. The larval densities varied greatly from 0.01 to 33 larvae/dip; likewise the adult densities, recorded in animal shelters, varied from < 10 to > 1000 female/shelter. The higher adult densities were recorded in Calabria, along the West coast. The other important vector in Southern Italy, A. superpictus, was found both in the West and East coasts of the same region, showing low larval and adult densities. Anopheles sacharovi, that was an important malaria vector in Puglia and Sardinia, was not found. Four populations of A. labranchiae were tested to determine the susceptibility to some insecticides. All of these populations were fully susceptible to deltamethrin, malathion and DDT, while showed a reduced susceptibility to permethrin and propoxur.

Animals↗
PubMed1992

Ultrastructural findings of congenital dyserythropoietic sickle cell beta thal-associated anemia.

The ultrastructural findings of erythroblasts and reticulocytes in one case of congenital dyserythropoiethic anemia (CDA) associated with a haemoglobinopathy, sickle cell beta thalassemia minor (Type V CDA), is described. The observations can be summarized as follows: 1) A lot of large breaks are present in the erythroblast nuclear envelope. 2) Nuclear membrane evaginations are filled with dense loose chromatin. 3) Electron-transparent areas (moth eaten chromatin) are evident in dense chromatin. 4) Electron-dense granular material, related to altered haemoglobin chain storage, is evident in the nucleus and in the cytoplasm. 5) Iron deposits are present in mitochondrial matrix. 6) Myelinic figures are present in reticulocyte cytoplasm. For the first time the ultrastructural findings in this type of associated CDA are described and related to the double origin of clinical symptoms.

Anemia, Dyserythropoietic, Congenital↗
PubMed1991

Density profiles of biological specimens from Tiff files.

A program for achieving density profiles of Tiff images is described. Densitometric analysis is performed applying a cross-lateral averaging and longitudinal interpolation along the image axis. These procedures may be adapted to a variable axis curvature, length, width and morphological resolution. Since the Tiff format is supported by all desktop scanners and a large number of frame-grabbing devices, the range of applications includes the analysis of light and electron micrographs, autoradiograms, chromatograms, and data from any kind of bidimensional medium or flat surface. A special feature is the possibility of retrieving data from published pictures taken from literature.

Biology↗
PubMed1990

Inter- and intraspecific heterochromatin variation detected by restriction endonuclease digestion in two sibling species of the Anopheles maculipennis complex.

The sibling species Anopheles atroparvus and Anopheles labranchiae are cytogenetically almost indistinguishable. The chromosome complement (2n = 6) consists of two pairs of autosomes and two heteromorphic sex chromosomes with largely homologous heterochromatic long arms. Treatment of chromosome preparations with the restriction endonucleases, Alu I, Hae III, Mbo I, Hpa II, revealed species-specific differences of the sex chromosome banding pattern. These differences involved both amount and location of digested heterochromatin. Heterochromatin heterogeneity and a high level of intraspecific polymorphism, undetected with standard banding techniques, were observed in both species. Quantitative heterochromatin differences between the sex chromosomes did not inhibit their pairing and chiasmata formation. The endonuclease Msp I, which cleaves the same target sequence as Hpa II, did not digest heterochromatic as well as euchromatic regions in both species: inhibition of cleavage by methylation of the target sequence or limited access of the enzyme to the target could be involved in this response.

Animals↗