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Biomedical subjects

S Gigliotti

Publications and source records attributed to S Gigliotti.

18 recordsLinked to original sources
PubMed2001

Interactive navigation system for shock wave applications.

The latest generation of shock wave lithotripters, with therapy heads mounted on articulated arms, have found widespread application in the treatment of orthopedic diseases. Currently, integration of an ultrasound probe in the therapy head is the dominant modality for positioning the shock wave focus on the treatment area. For orthopedic applications, however, X-ray imaging is often preferred. This article describes a new method to locate the therapy head of a lithotripter. In the first step, the surgeon positions the tissue to be treated at the isocenter of a C-arc. This is achieved using AP and 30-degree lateral projections, with corresponding horizontal and vertical movements of the patient under fluoroscopic guidance. These movements register the anatomic location in the coordinate system of the C-arc. In the second step, the therapy head is navigated to align the shock wave focus with the isocenter. Position data are reported from an optical tracker mounted on the X-ray system, which tracks an array of infrared LEDs on the therapy head. The accuracy of the tracking system was determined on a test bench, and was calculated to be 1.55 mm (RMS) for an angular movement of +/-15 degrees around a calibrated position. Free-hand navigation and precise alignment are performed with a single virtual reality display. The display is calculated by a computer system in real time, and uses graphical symbols to represent the shock wave path and isocenter. In an interactive process, the physician observes the display while navigating the therapy head towards the isocenter. Precise alignment is achieved by displaying an enlarged view of the intersecting graphical symbols. Results from the first tests on 100 patients demonstrate the feasibility of this approach in a clinical environment.

Computer Simulation↗
PubMed2000

Female sterile mutations and egg chamber development in Drosophila melanogaster.

Drosophila oogenesis provides an excellent opportunity to study fundamental aspects of developmental biology and to learn the importance of multiple signalling pathways in the regulation of cellular morphogenesis. Taking advantage of the genetic and molecular approaches extremely powerful in this organism, over the years an enormous collection of data has accumulated on the genes involved in important steps of egg chamber development, such as germline and somatic stem cell maintenance, division and differentiation; oocyte determination and positioning; establishment of follicle cell fate and axes formation. These different processes are mediated by a reciprocal cross-talk between germline and somatic follicle cells. Here, in a schematic and simplified form, we point out what we believe are the main recent results on the molecular and cellular mechanisms underlying ovarian development and outline our recent contribution to this field.

Amino Acid Sequence↗
PubMed1999

Developmental genetics of the essential Drosophila nucleoporin nup154: allelic differences due to an outward-directed promoter in the P-element 3' end.

Drosophila nup154 encodes a predicted nucleoporin homologous to yeast Nup170p, Nup157p, and vertebrate Nup155, all of which are major components of the nuclear pore complex (NPC). Unlike its yeast homologs, nup154 is essential for viability. Animals with strong loss-of-function nup154 mutations caused by P-element insertion in the 5'-UTR of the gene died as larvae with small discs, brains, and testes. nup154 mRNA expression appeared developmentally regulated in tissues of wild-type embryos, larvae, and adults, suggesting that new nup154 synthesis is required when assembly of new NPCs is required, as in proliferating or growing tissues. Two additional nup154 alleles also associated with different P-element inserts in the 5'-UTR were viable but had strong loss-of-function sterile phenotypes, including failure to maintain spermatogenic stem cells and failure to progress into vitellogenic stages of oogenesis. Lethality vs. viability correlated with orientation of the P-element inserts in the different alleles. Transcript analysis by 5'-RACE suggested a mechanism for allelic differences: an outward-directed promoter internal to the P-element 3' end able to drive sufficient expression of the nup154 transcript for viability but not for fertility.

Animals↗
PubMed1998

Nup154, a new Drosophila gene essential for male and female gametogenesis is related to the nup155 vertebrate nucleoporin gene.

The Nup154 gene of Drosophila encodes a protein showing similarity with known nucleoporins: rat Nup155 and yeast Nup170 and Nup157. Hypomorphic mutant alleles of Nup154 affected female and male fertility, allowing investigation of the gene function in various steps of oogenesis and spermatogenesis. Nup154 was required in testes for cyst formation, control of spermatocyte proliferation and meiotic progression. In ovaries, Nup154 was essential for egg chamber development and oocyte growth. In both the male and female germ line, as well as in several other cell types, the Nup154 protein was detected at the nuclear membrane, but was also present inside the nucleus. Intranuclear localization has not previously been described for rat Nup155 or yeast Nup170 and Nup157. In mutant egg chambers the Nup154 protein accumulated in the cytoplasm, while it was only barely detected at the nuclear envelopes. FG repeats containing nucleoporins detected with mAb414 antibody were also mislocalized to a certain extent in Nup154 mutant alleles. This suggests that Nup154 could be required for localizing other nucleoporins within the nuclear pore complex, as previously demonstrated for the yeast Nup170. On the other hand, no evident defects in lamin localization were observed, indicating that Nup155 mutations did not affect the overall integrity of the nuclear envelope. However, ultrastructural analyses revealed that in mutant cells the morphology of the nuclear envelope was altered near the nuclear pore complexes. Finally, the multiplicity of phenotypes observed in Nup154 mutant alleles suggests that this gene plays a crucial role in cell physiology.

Amino Acid Sequence↗
PubMed1997

Organisation of regulatory elements in two closely spaced Drosophila genes with common expression characteristics.

Sperm tail proteins that are components of a specific structure formed late during spermatid elongation have been found to be encoded by the Mst(3)CGP gene family. These genes have been demonstrated to be regulated both at the transcriptional as well as at the translational level. We report here on the dissection of the regulatory regions for two members of the gene family, Mst84Da and Mst84Db. While high level transcription and negative translational control of Mst84Da is mediated by a short gene segment of 205 nt (-152/+53), Mst84Db expression is controlled by a number of distinct regulatory elements with different effects that all reside within the gene itself. We identify a transcriptional control element between +154 and +216, a translational repression element around +216 to +275 and an RNA stability element within the 3'UTR. Irrespective of the final common expression characteristics, correct regulation for any individual member of the gene family seems to be achieved by very different means. This confirms earlier observations that did not detect any other sequence elements in common apart from the TCE (translational control element).

Animals↗
PubMed1993

A membrane guanylate cyclase Drosophila homolog gene exhibits maternal and zygotic expression.

A putative membrane form of guanylate cyclase gene was identified in region 32 of the second chromosome of Drosophila melanogaster. The Drosophila protein has a single hydrophobic sequence that divides the protein into a putative extracellular region and a cytoplasmic catalytic region which contains tyrosine kinase and cyclase domains showing varying degrees of conservation with other guanylate and adenylate cyclases. The gene shows a very interrupted organization with small exons separated by small introns and a low level of expression. Transcripts have been localized in situ during oogenesis in the germarium and later in stages 10-14 of egg chamber development. The putative maternal transcript can be seen in very early embryos and reappears later as a product of zygotic gene expression.

Amino Acid Sequence↗
PubMed1991

Cellular specificity of expression and regulation of Drosophila vitelline membrane protein 32E gene in the follicular epithelium: identification of cis-acting elements.

In this paper we analyze the expression in follicular cells and regulation of the vitelline membrane protein gene we identified in region 32E of the second chromosome of D. melanogaster (VMP32E). We report germ line transformation results obtained with different kinds of gene fusion leading to the identification of a follicular cell subpopulation involved in the expression of the VMP32E. We have characterized two 5' non-transcribed regions (-465/-249; -135/-39) where the cis-acting transcriptional regulatory sequences, directing tissue and temporal specificity, are contained. The region between -465 and -249, which appears to control transcriptional high efficiency, does not behave as an enhancer as it is incapable of conferring any expression to a reporter gene. The region between -135 and -39 can confer temporal specificity of expression of the VMP32E gene, albeit at a very low level. Most interestingly, sequence similarities to ecdysone response elements raise the possibility of hormonal control also for VMP gene expression.

Animals↗
PubMed1990

A case of osteoporosis associated with adenosine deaminase deficiency.

The authors report a case of early and marked osteoporotic syndrome in a patient affected with adenosine-deaminase deficiency (ADA) of the heterozygotic type. The negative results obtained in all the tests carried out to ascertain any dysmetabolic, nutritional or iatrogenic disease, and the literature reporting homozygotic patients with osteometabolic and skeletal changes similar to those observed in this particular patient, led the authors to suggest a possible pathogenetic role in ADA deficiency. They conclude by describing the mechanisms by which this enzymatic defect could determine the clinical picture, and by presenting a possible type of treatment.

Adenosine Deaminase↗
PubMed1990

[Chondromas and chondrosarcomas of the hand: their surgical treatment and the long-term results].

Authors show various techniques utilized in surgical treatment of forty-nine hand chondromas, specifying indications, advantages and long term results, and refer on one case with beginning malignancy and one case of chondrosarcoma in the hand. By analysis of clinical, roentgenographic, pathological and evolutive pictures they discuss on their conclusions in malignancy criteria, reporting their surgical choices in treatment of hand chondrogenic malignant tumors.

Aged↗
PubMed1990

[Paget's disease: a case history, clinical and therapeutic contribution].

The authors, after referring the various pathogenetic hypotheses for Paget's disease (till the latest hypothesis of infection by slow-action virus) report their follow-up of forty-five patients with Paget's disease of bone; then explain their diagnostic method, and record complications stressing the sarcomatous degeneration. Finally they give details on their therapeutic treatment emphasizing the need of hematochemical and radiographic periodical controls in order to optimize the treatment case by case.

Adult↗
PubMed1990

Aneurysmal bone cysts in the hand.

The authors emphasize the rarity of aneurysmal bone cysts localised in the hand. They report three cases and describe the radiographic, macroscopic and histological appearances. These three cases were out of a total of 350 tumours of the hand. The surgical treatment is described, also the differential diagnosis and the criteria used to select the type of surgery adopted.

Adolescent↗
PubMed1989

Sex-, tissue-, and stage-specific expression of a vitelline membrane protein gene from region 32 of the second chromosome of Drosophila melanogaster.

This study isolated cDNA clones from egg-chamber and adult female Drosophila cDNA libraries using as probe a DNA fragment from a 200-kb "chromosome walk" in region 32E of the second chromosome of D. melanogaster. The present authors believe that these clones correspond to a new vitelline membrane protein (VMP) gene because 1) cDNA clones in Northern blots identify a transcript expressed in a tissue- and stage-specific manner: stage 10 egg-chambers; 2) the sequence of cDNAs and of the genomic subclone shows homology with the other VMP genes that have been identified to date; 3) the amino acid composition of the translational product has the high content of proline and alanine characteristic of VMPs. Two aspects emerging from this study are worth stressing: 1) the presence of a hydrophobic domain that is highly conserved in all the VMP genes; and 2) the particularly narrow period of expression of the isolated gene, which could be related to the mechanism of vitelline membrane assembly.

Amino Acid Sequence↗
PubMed1989

Genomic distribution of copia-like transposable elements in somatic tissues and during development of Drosophila melanogaster.

The genomic distribution of elements of the copia, 412, B 104, mdg 1, mdg 4 and 1731 transposon families was compared by the Southern technique in DNA preparations extracted from brains, salivary glands and adult flies of two related Drosophila lines. The copia, 412 and mdg 1 sequences were also probed in DNA from sperm, embryos, and 1st and 2nd instar larvae. The homogeneity of the patterns observed shows that somatic transposition is unlikely to occur frequently. A correlation between mobility and the euchromatic or heterochromatic location of transposable elements is discussed. In addition, an explanation of the variable band intensities of transposable elements in Southern autoradiographs is proposed.

Animals↗
PubMed1989

The abnormal oocyte phenotype is correlated with the presence of blood transposon in Drosophila melanogaster.

The abnormal oocyte mutation (2;44) originates in the wild: it confers no visible phenotype on homozygous abo males or females, but homozygous abo females produce defective eggs and the probability of their developing into adults is much lower than that of heterozygous sister females. We isolated by chromosome walking 200 kb of DNA from region 32. This paper reports that a restriction enzyme site polymorphism analysis in wild type and mutant stocks allowed us to identify a DNA rearrangement present only in stocks carrying the abo mutation. The rearrangement is caused by a DNA insert on the abo chromosome in region 32E which, by restriction map and sequence analysis, was identified as copia-like blood transposon. The transposon, in strains that had remained in abo homozygous conditions for several generations and had lost the abo maternal-effect, was no longer present in region 32E. Certain features of the abo mutation, discussed in the light of this finding, may be ascribed to the nature of the particular allele studied.

Animals↗
PubMedDate not supplied

Surgical synovectomy in the treatment of rheumatoid arthritis: the results obtained in a controlled study.

The authors report the long-term results obtained after 2 and 4 years in a controlled study conducted on surgical synovectomies performed in articular and extra-articular regions in rheumatoid arthritis. Out of a total of 157 patients submitted to surgery between 1977 and 1987 admitted to the study were 82 patients with bilateral symmetric localizations, but who had been submitted to synovectomy only unilaterally. The collection and interpretation of data showed that synovectomy is truly effective and that clinical improvements is not related to a spontaneous regression in the rheumatoid process. Surgery must be performed when the degree of osteocartilaginous deficit is absent or moderate. It does not avoid local recurrence, but it does obtain an antalgic effect, better joint excursion, and a slowing down in the destructive osteocartilaginous processes.

Adolescent↗
PubMedDate not supplied

Fractures in Paget's disease.

After analyzing the various types of anatomical and radiographic fractures in pagetic bone, the authors explain the reason for their preference for surgical treatment if the lesion is localized in the lower limbs. This choice allows for a reduction in the duration of immobilization and a lowered incidence of local (rapid and intense osteolysis of the pagetic bone) and general complications (hypercalciuria, at times, hypercalcemia). It is best to resort to internal osteosynthesis for diaphyseal fractures and prosthetic substitution for fractures of the femoral neck where treatment with screws and plates is less reliable due to the fragility of the pagetic bone. Non-surgical treatment may be used for fractures of the upper limb as the duration of the consolidation process, which is always increased, at any rate remains restricted to acceptable limits. Nonetheless, the radiographic occurrence of repair callus is not a sure sign of healing as it may also be affected by the Paget's disease.

Aged↗
PubMedDate not supplied

[Hand injuries due to fireworks explosion].

Two different series of patients with burst injuries of the hand were retrospectively reviewed: one series included 23 men, 15-55 years old, referred to the emergency department for the first-instance assessment of injuries of the right hand (13 patients) and left hand (10 patients). The other series included 44 patients (42 men and 2 women, aged 7-61 years) referred to our department for second-instance examinations: the latter patients had burst injuries involving only the hands in 43 cases and both the hand and the foot in one case. We report the radiologic patterns of traumatic bone injuries (fractures and amputations) and of musculotendinous and cutaneous injuries and discuss their mechanisms and pathogenesis. The two series were compared and the results follow: in both series the right hand was more frequently involved, metacarpal bones were most often fractured and phalanges most often amputated. In the first series, in the right hand the carpal bones were involved in one patient only, the 2nd and 3rd metacarpal bones were most frequently fractured and the 2nd finger was most frequently involved. In the left hand, the carpal bones were never affected, the 1st metacarpal bone was most often amputated and the 5th metacarpal bone most often fractured; the 2nd finger was most frequently involved. In the second series, in the right hand, the 1st metacarpal bone was most frequently fractured and the 2nd metacarpal bone most often amputated; the 2nd finger was most frequently involved. In the left hand, the 4th metacarpal bone was most frequently fractured and the 5th metacarpal bone most often amputated. The severity of the above injuries and the extent of tissue damage depend on several factors, including firecracker speed, shape, size, weight and characteristics. Radiologic exams are very useful for the accurate study of these traumatic injuries, providing indirect information about musculotendinous and cutaneous involvement. Prompted by the relative lack of information on the management of these injuries, we suggest that radiologic exams be quickly performed to help choose the most appropriate surgical approach for best cosmetic and functional results.

Adolescent↗