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1.
Eur Rev Med Pharmacol Sci ; 27(10): 4670-4677, 2023 05.
Article in English | MEDLINE | ID: mdl-37259750

ABSTRACT

OBJECTIVE: The Italian Society of Anesthesia, Analgesia, Reanimation and Intensive Care Medicine (SIAARTI) and the Italian Society of Digestive Endoscopy (SIED) worked together to produce a joint Good Clinical Practice (GCP) on analgo-sedation in digestive endoscopy and launched a survey to support the document. The aim was to identify and describe the actual clinical practice of sedation in Italian digestive endoscopy units and offer material for a wider and more widespread discussion among anesthetists and endoscopists. SUBJECTS AND METHODS: A national survey was planned, in order to support the statements of the GCP. Twelve thousand and five hundred questionnaires were sent to the members of SIAARTI and SIED in June 2020. RESULTS: A total of 662 forms (5.3%) returned completed. Highly complex procedures are performed according to 70% of respondents; daily anesthesiologist's assistance is guaranteed in 26%, for scheduled sessions in 14.5% and as needed in 8%. 69% of respondents declared not to have a dedicated team of anesthesiologists, while just 5% reported an anesthesiologist in charge. A complete monitoring system was assured by 70% of respondents. Dedicated pathways for COVID-19-positive patients were confirmed in <40% of the answers. With regard to moderate/deep sedation, 90% of respondents stated that an anesthetist decides timing and doses. Propofol was exclusively administered by anesthetists according to 94% of answers, and for 6% of respondents the endoscopist is allowed to administer propofol in presence of a dedicated nurse, but with a readily available anesthetist. Only 32.8% of respondents reported institutional training courses on procedural analgo-sedation. CONCLUSIONS: The need to provide patients scheduled for endoscopy procedures with an adequate analgo-sedation is becoming an increasing concern, well-known in almost all countries, but many factors compromise the quality of patient care. Results of a national survey would give strength to the need for a shared GCP in gastrointestinal endoscopy. Training and certification of non-anesthetist professionals should be one of the main ways to center the objective.


Subject(s)
Anesthesia , COVID-19 , Propofol , Humans , Hypnotics and Sedatives , Societies, Scientific , Endoscopy, Gastrointestinal/methods , Conscious Sedation/methods
3.
Dig Liver Dis ; 39(11): 1024-9, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17913605

ABSTRACT

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized study was to compare the standard regimen of midazolam and pethidine administered by the gastroenterologist versus patient controlled sedation with a propofol-fentanyl mixture during upper gastrointestinal tract endoscopic ultrasonography. Our primary end-points were patient satisfaction and patient cooperation assessed by endoscopist. METHODS: Fifty-four consecutive patients, undergoing endoscopic ultrasonography, received sedation with midazolam and pethidine (Group M: n=27) or propofol and fentanyl (Group P: n=27). Group M: pethidine 0.7mg/kg midazolam 0.04mg/kg before examination; boluses of same drugs if the sedation was insufficient plus a sham patient controlled sedation analgesia; Group P: propofol 17mg plus fentanyl 15microg before examination and a patient controlled sedation analgesia pump containing 170mg propofol plus 150microg fentanyl injecting 0.5ml every time the patient pressed the button (no "lock out"). Boluses of 1ml of the same mixture if the sedation was insufficient. RESULTS: Group M: mean dosage of pethidine and midazolam 88.6 and 5mg, respectively. Group P: mean dosage of propofol and fentanyl 119.7mg and 106microg, respectively. Both groups were similar for duration and difficulty of the procedure, the grade of sedation (Observer's Assessment of Alertness/Sedation Score) and judgement by endoscopist and patient about cooperation and satisfaction. The only difference between groups was about the extra boluses administered during the procedure. CONCLUSION: This study demonstrated that a patient controlled sedation analgesia with propofol and fentanyl is an effective and safe technique for upper gastrointestinal tract endoscopic ultrasonography procedures and results in a high level of satisfaction both for patients and operator.


Subject(s)
Adjuvants, Anesthesia/administration & dosage , Analgesia, Patient-Controlled , Analgesics, Opioid/administration & dosage , Conscious Sedation/methods , Endosonography , Fentanyl/administration & dosage , Hypnotics and Sedatives/administration & dosage , Meperidine/administration & dosage , Midazolam/administration & dosage , Propofol/administration & dosage , Upper Gastrointestinal Tract/diagnostic imaging , Aged , Analgesia, Patient-Controlled/standards , Conscious Sedation/standards , Endosonography/methods , Female , Humans , Male , Middle Aged , Patient Compliance , Patient Satisfaction , Prospective Studies
4.
Dig Liver Dis ; 39(1): 81-6, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17049322

ABSTRACT

BACKGROUND: It has been speculated that midazolam may be effective in reducing the required dose of propofol during sedation. AIM: To evaluate the sparing effect of midazolam during target-controlled propofol infusion. METHODS: Two hundred-seventy patients undergoing upper endoscopic ultrasound were randomised to receive sedation with propofol plus placebo (group A) or plus midazolam (group B). Outcome parameters were the procedure duration, the discharge time and the satisfaction of patients, operator and nurse about the quality of sedation. RESULTS: The mean propofol dose administered was 364+/-207 mg in group A and 394+/-204 mg in group B. Mean procedure duration (group A: 32+/-17 min, group B: 35+/-22 min) and discharge time (group A: 39+/-30 min, group B: 38+/-24 min) were similar in both groups. No severe complications were observed. The quality of sedation was judged satisfactory for all patients by both the endoscopist and the nurse assistant without any difference between the two groups. No patient remembered the procedure or reported it as unpleasant. CONCLUSIONS: Target-controlled propofol infusion provides safe and effective sedation; premedication with low dose of midazolam does not reduce the total amount of propofol administered. Further studies are needed to compare propofol alone with propofol co-administered with opioid.


Subject(s)
Anesthetics, Intravenous/administration & dosage , Gastroscopy/methods , Infusion Pumps , Midazolam/administration & dosage , Monitoring, Physiologic , Propofol/administration & dosage , Aged , Aged, 80 and over , Double-Blind Method , Drug Combinations , Female , Humans , Male , Middle Aged , Outcome and Process Assessment, Health Care , Patient Satisfaction , Prospective Studies
5.
Cytogenet Genome Res ; 110(1-4): 124-33, 2005.
Article in English | MEDLINE | ID: mdl-16093664

ABSTRACT

Drosophila melanogaster telomeres contain arrays of two non-LTR retrotransposons called HeT-A and TART. Previous studies have shown that HeT-A- and TART-like sequences are also located at non-telomeric sites in the Y chromosome heterochromatin. By in situ hybridization experiments, we mapped TART sequences in the h16 region of the long arm close to the centromere of the Y chromosome of D. melanogaster. HeT-A sequences were localized in two different regions on the Y chromosome, one very close to the centromere in the short arm (h18-h19) and the other in the long arm (h13-h14). To assess a possible heterochromatic location of TART and HeT-A elements in other Drosophila species, we performed in situ hybridization experiments, using both TART and HeT-A probes, on mitotic and polytene chromosomes of D. simulans, D. sechellia, D. mauritiana, D. yakuba and D. teissieri. We found that TART and HeT-A probes hybridize at specific heterochromatic regions of the Y chromosome in all Drosophila species that we analyzed.


Subject(s)
Chromosome Mapping , Retroelements/genetics , 3' Untranslated Regions/genetics , Animals , Drosophila melanogaster , Gene Rearrangement , In Situ Hybridization, Fluorescence , Open Reading Frames , Telomere/genetics
6.
Hepatogastroenterology ; 49(47): 1296-7, 2002.
Article in English | MEDLINE | ID: mdl-12239929

ABSTRACT

BACKGROUND/AIMS: Helicobacter pylori infection has a low prevalence in Crohn's disease, possibly because of sulphasalazine therapy. We investigated Helicobacter pylori seroprevalence in patients with Crohn's disease never treated with sulphasalazine in order to assess the possible role of antibiotic treatment. METHODOLOGY: Two groups of patients with Crohn's disease (group I: subjects treated with ciprofloxacin, metronidazole or both during the last six months; Group II: subjects who were not given antibiotics during the last six months) and a control group of 30 patients with irritable bowel syndrome were considered. IgG anti-H. pylori levels were measured in all patients. RESULTS: Serology was positive respectively in 16.6%, 13.3% and 36.6% of cases in the three groups. CONCLUSIONS: Our findings confirm the Helicobacter pylori infection is infrequent in Crohn's disease. Neither sulphasalazine nor antibiotics appear to play a role.


Subject(s)
Crohn Disease/epidemiology , Crohn Disease/microbiology , Helicobacter Infections/epidemiology , Helicobacter pylori , Adolescent , Adult , Anti-Bacterial Agents/therapeutic use , Comorbidity , Crohn Disease/drug therapy , Female , Humans , Male , Seroepidemiologic Studies
7.
J Clin Pathol ; 55(5): 397-8, 2002 May.
Article in English | MEDLINE | ID: mdl-11986352

ABSTRACT

Human herpesvirus oesophagitis in human immunodeficiency virus positive patients is caused by cytomegalovirus and herpes simplex virus; no cases of oesophagitis and oesophagobrochial fistula as a result of varicella zoster virus (VZV) have been reported to date. This report describes the case of a patient with a 2-3 mm deep oesophageal ulcer whose viral culture was positive for VZV. The patient was treated with acyclovir with resolution of the symptomatology. After the end of the induction treatment, because of the onset of fever and fits of coughing during eating, the patient underwent oesophagography, which showed an ulcer with an oesophagobronchial fistula in the middle and lower third of the oesophagus. This case report stresses the role of VZV infection as a possible cause of oesophagobronchial fistula, a rare but benign condition in patients with AIDS.


Subject(s)
AIDS-Related Opportunistic Infections/complications , Bronchial Fistula/virology , Esophageal Fistula/virology , Herpes Zoster/complications , Adult , Homosexuality, Male , Humans , Male
8.
Proc Natl Acad Sci U S A ; 98(21): 12126-31, 2001 Oct 09.
Article in English | MEDLINE | ID: mdl-11593026

ABSTRACT

The abnormal oocyte (abo) gene of Drosophila melanogaster is a peculiar maternal effect gene whose mutations cause a maternal-effect lethality that can be rescued by specific regions of heterochromatin during early embryogenesis. Here we show that abo encodes an evolutionary conserved chromosomal protein that localizes exclusively to the histone gene cluster and binds to the regulatory regions of such genes. We also show a significant increase of histone transcripts in eggs of abo mutant mothers and a partial rescue of the abo maternal-effect defect by deficiencies of the histone gene cluster. On the basis of these results, we suggest that the Abo protein functions specifically as a negative regulator of histone transcription and propose a molecular model to account for the ability of heterochromatin to partially rescue the abo maternal-effect defect. Our model proposes that increased doses of specific heterochromatic regions titrate out abnormally high levels of histones present in embryos from mutant abo mothers and that a balanced pool of histones is critical for normal embryogenesis in Drosophila.


Subject(s)
Drosophila Proteins/genetics , Genes, Insect , Histones/metabolism , Insect Proteins/genetics , Nuclear Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Female , Insect Proteins/metabolism , Molecular Sequence Data , Nuclear Proteins/metabolism , Sequence Homology, Amino Acid
9.
J Clin Gastroenterol ; 32(1): 45-8, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11154169

ABSTRACT

We assessed both the effectiveness of two Helicobacter pylori (Hp) eradication triple therapies and the usefulness of serology in the follow-up. Fifty patients with active or scarred duodenal ulcer were randomized to lansoprazole or omeprazole for 1 to 4 weeks, with clarithromycin 250 mg twice a day and tinidazole 500 mg twice a day for the first week. Endoscopies were scheduled before treatment, after 8 weeks, and after I year. H. pylori status was determined before therapy by rapid urease test and histology and during the follow-up by histology and culture. Serology was determined at baseline and at 6 and 12 months. The regimens were equally effective in inducing ulcer healing (95.8% vs. 87.5%) and eradicating Hp with no recurrences at 12 months. Among 44 patients eradicated, a significant reduction of immunoglobulin G (IgG) titer occurred at 6 (p < 0.0001) and 12 months (p < 0.0001). If a titer reduction of more than 30% was taken as an indicator for Hp eradication, the specificity of enzyme-linked immunosorbent assay was 75% at 6 and 95.4% at 12 months with a 100% sensitivity. Either lansoprazole or omeprazole combined with antibiotics are effective in eradicating Hp. Serology is useful for monitoring Hp eradication provided that an appropriate percent reduction in IgG titer is used after more then 6 months after therapy.


Subject(s)
Anti-Ulcer Agents/therapeutic use , Duodenal Ulcer/drug therapy , Duodenal Ulcer/microbiology , Helicobacter Infections/drug therapy , Helicobacter pylori/immunology , Omeprazole/analogs & derivatives , Omeprazole/therapeutic use , 2-Pyridinylmethylsulfinylbenzimidazoles , Adult , Anti-Bacterial Agents/therapeutic use , Antibodies, Bacterial/blood , Clarithromycin/therapeutic use , Drug Therapy, Combination , Duodenal Ulcer/immunology , Female , Follow-Up Studies , Helicobacter Infections/immunology , Helicobacter Infections/microbiology , Humans , Immunoglobulin G/biosynthesis , Lansoprazole , Male , Middle Aged , Sensitivity and Specificity , Tinidazole/therapeutic use
10.
Mol Cell ; 5(2): 355-65, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10882076

ABSTRACT

Drosophila ISWI, a highly conserved member of the SWI2/SNF2 family of ATPases, is the catalytic subunit of three chromatin-remodeling complexes: NURF, CHRAC, and ACF. To clarify the biological functions of ISWI, we generated and characterized null and dominant-negative ISWI mutations. We found that ISWI mutations affect both cell viability and gene expression during Drosophila development. ISWI mutations also cause striking alterations in the structure of the male X chromosome. The ISWI protein does not colocalize with RNA Pol II on salivary gland polytene chromosomes, suggesting a possible role for ISWI in transcriptional repression. These findings reveal novel functions for the ISWI ATPase and underscore its importance in chromatin remodeling in vivo.


Subject(s)
Adenosine Triphosphatases/metabolism , Chromatin/ultrastructure , Chromosomes/ultrastructure , DNA-Binding Proteins , Drosophila Proteins , Gene Expression , Transcription Factors/metabolism , X Chromosome/ultrastructure , Acetylation , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/isolation & purification , Animals , Cell Survival , Drosophila/anatomy & histology , Drosophila/embryology , Drosophila/genetics , Euchromatin , Female , Fluorescent Antibody Technique , Genes, Essential , Heterochromatin/ultrastructure , Homeodomain Proteins/isolation & purification , Homeodomain Proteins/metabolism , Male , Mitosis , Mutation , Phenotype , Transcription Factors/genetics , Transcription Factors/isolation & purification
11.
EMBO Rep ; 1(3): 253-9, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11256608

ABSTRACT

SAP18, a polypeptide associated with the Sin3-HDAC co-repressor complex, was identified in a yeast two-hybrid screen as capable of interacting with the Drosophila GAGA factor. The interaction was confirmed in vitro by glutathione S-transferase pull-down assays using recombinant proteins and crude SL2 nuclear extracts. The first 245 residues of GAGA, including the POZ domain, are necessary and sufficient to bind dSAP18. In polytene chromosomes, dSAP18 and GAGA co-localize at a few discrete sites and, in particular, at the bithorax complex where GAGA binds some silenced polycomb response elements. When the dSAP18 dose is reduced, flies heterozygous for the GAGA mutation Trl67 show the homeotic transformation of segment A6 into A5, indicating that GAGA-dSAP18 interaction contributes to the functional regulation of the iab-6 element of the bithorax complex. These results suggest that, through recruitment of the Sin3-HDAC complex, GAGA might contribute to the regulation of homeotic gene expression.


Subject(s)
Carrier Proteins , Drosophila Proteins , Drosophila/embryology , Histone Deacetylases/metabolism , Homeodomain Proteins/metabolism , Transcription Factors/metabolism , Abdomen/embryology , Amino Acid Sequence , Animals , Autophagy-Related Proteins , Binding Sites , Choristoma/genetics , Chromosomes/genetics , Chromosomes/metabolism , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Drosophila/genetics , Drosophila/metabolism , Homeodomain Proteins/chemistry , Homeodomain Proteins/genetics , Insect Proteins/chemistry , Insect Proteins/genetics , Insect Proteins/metabolism , Male , Mi-2 Nucleosome Remodeling and Deacetylase Complex , Molecular Sequence Data , Mutation , Phenotype , Protein Binding , Protein Structure, Tertiary , Saccharomyces cerevisiae Proteins , Sequence Alignment , Sequence Homology, Amino Acid , Sin3 Histone Deacetylase and Corepressor Complex , Transcription Factors/chemistry , Transcription Factors/genetics , Two-Hybrid System Techniques
12.
Digestion ; 60(5): 456-60, 1999.
Article in English | MEDLINE | ID: mdl-10473970

ABSTRACT

BACKGROUND/AIM: Several diagnostic tests are available for evaluating Helicobacter pylori (Hp) infection: histological examination, culture of gastric biopsy specimens, rapid urease test, urea breath test and serology. A recently marketed direct enzyme immunoassay (HpSA) detects Hp antigen in stool samples. The aim of our study was to evaluate overall diagnostic sensitivity, specificity and positive and negative predictive values of this new diagnostic test. METHODS: We included in the study 84 patients (39 males and 45 females; mean age 49.57 years) with dyspeptic symptoms who were examined by upper gastrointestinal endoscopy. Exclusion criteria were previous treatment with proton pump inhibitors, bismuth compounds or antibiotics. During the endoscopic examination biopsies were taken from antrum and corpus for Hp culture and histological examination, and stool specimens were submitted to the laboratory to be stored until the HpSA test. Hp was judged to be present when culture or histology and culture were positive. The (13)C-urea breath test was done only in culture-negative patients in whom either histology or immunoassay or both were positive. RESULTS: Hp was found in 55 patients by both culture and histology. Stool antigen has been detected in 54 of the 55 Hp-positive patients, giving a sensitivity of 98.2% and a negative predictive value of 96.4%. In 2 out of 29 patients HpSA gave a positive result, but the biopsy-based methods were negative, resulting in a low rate of false-positives, with 93.1% specificity and 96.4% positive predictive value; the (13)C-urea breath test confirmed these results as negative. CONCLUSION: Our results show that this new test is highly sensitive and specific for the detection of Hp infection, and it is satisfactorily reproducible.


Subject(s)
Antigens, Bacterial/analysis , Feces/microbiology , Helicobacter Infections/diagnosis , Helicobacter pylori/immunology , Adult , Aged , Breath Tests , Evaluation Studies as Topic , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , Predictive Value of Tests , Reproducibility of Results , Sensitivity and Specificity
13.
Eur J Gastroenterol Hepatol ; 11(7): 781-4, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10445800

ABSTRACT

OBJECTIVE: Pre-operative endoscopic retrograde cholangiography (ERCP) prior to laparoscopic cholecystectomy (LC) is the most common treatment of gallbladder and common bile duct (CBD) stones. In this study we evaluate our selection criteria for pre-operative ERCP and the results of endoscopic-laparoscopic treatment in patients with CBD stones. DESIGN: Consecutive adult patients admitted to the department of surgery because of symptomatic cholelithiasis were included in a prospective open trial. PARTICIPANTS: Between January 1996 and December 1996, 841 patients underwent LC at our hospital. ERCP pre-LC was performed in 95 of the 841 patients, on the basis of our selection criteria. INTERVENTIONS: The indication to perform ERCP was suggested by a dilatated CBD (> 10 mm) or ductal stones, abnormal serum liver tests, persisting for more than 3 days, jaundice, cholangitis or pancreatitis. Twelve months after surgery, all patients were contacted by telephone to exclude symptoms related to residual stones. RESULTS: Cannulation of the CBD was successful in 94 of 95 patients submitted to pre-LC ERCP. CBD stones were found in 87 patients (95.6%) in 22 of whom (25.2%) they were in the form of small stones or sludge. In only three of 94 patients (3.2%) no alterations of the CBD or papilla were found. Complications occurred in eight of 98 patients (in five after endoscopic sphincterotomy (ES), and in three after LC). CONCLUSIONS: Pre-operative ES in selected patients with coexisting gallbladder and CBD stones has been a good approach and the criteria that we used for selection of patients to be submitted to pre-operative ERCP/ES seem to be effective.


Subject(s)
Cholangiopancreatography, Endoscopic Retrograde , Cholelithiasis/surgery , Laparoscopy , Patient Selection , Adolescent , Adult , Aged , Aged, 80 and over , Female , Gallstones/surgery , Humans , Male , Middle Aged , Preoperative Care , Prospective Studies , Treatment Outcome
14.
EMBO J ; 18(13): 3820-33, 1999 Jul 01.
Article in English | MEDLINE | ID: mdl-10393197

ABSTRACT

The centromeric dodeca-satellite of Drosophila forms altered DNA structures in vitro in which its purine-rich strand (G-strand) forms stable fold-back structures, while the complementary C-strand remains unstructured. In this paper, the purification and characterization of DDP1, a single-stranded DNA-binding protein of high molecular mass (160 kDa) that specifically binds the unstructured dodeca-satellite C-strand, is presented. In polytene chromosomes, DDP1 is found located at the chromocentre associated with the pericentric heterochromatin but its distribution is not constrained to the dodeca-satellite sequences. DDP1 also localizes to heterochromatin in interphase nuclei of larval neuroblasts. During embryo development, DDP1 becomes nuclear after cellularization, when heterochromatin is fully organized, being also associated with the condensed mitotic chromosomes. In addition to its localization at the chromocentre, in polytene chromosomes, DDP1 is also detected at several sites in the euchromatic arms co-localizing with the heterochromatin protein HP1. DDP1 is a multi-KH domain protein homologous to the yeast Scp160 protein that is involved in the control of cell ploidy. Expression of DDP1 complements a Deltascp160 deletion in yeast. These results are discussed in view of the possible contribution of DNA structure to the structural organization of pericentric heterochromatin.


Subject(s)
DNA, Single-Stranded/metabolism , DNA-Binding Proteins/metabolism , Drosophila Proteins , Drosophila melanogaster/genetics , Heterochromatin/metabolism , Membrane Proteins/metabolism , Membrane Transport Proteins , Nuclear Proteins/metabolism , Ploidies , Saccharomyces cerevisiae Proteins , Amino Acid Sequence , Animals , Base Sequence , Binding, Competitive , Cell Nucleus/metabolism , Chromosomes/genetics , Chromosomes/metabolism , Cloning, Molecular , DNA, Satellite/genetics , DNA, Satellite/metabolism , DNA, Single-Stranded/genetics , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , DNA-Binding Proteins/isolation & purification , Drosophila melanogaster/cytology , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Fungal Proteins/chemistry , Fungal Proteins/genetics , Fungal Proteins/metabolism , Genetic Complementation Test , Heterochromatin/genetics , Insect Proteins/metabolism , Membrane Proteins/chemistry , Membrane Proteins/genetics , Mitochondrial Precursor Protein Import Complex Proteins , Molecular Sequence Data , Molecular Weight , Nuclear Proteins/chemistry , Nuclear Proteins/genetics , Nucleic Acid Conformation , RNA-Binding Proteins , Sequence Homology, Amino Acid , Yeasts/genetics
16.
Mol Cell ; 2(5): 527-38, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9844626

ABSTRACT

HP1 (Heterochromatin protein 1) is a conserved, non-histone chromosomal protein that is best known for its preferential binding to pericentric heterochromatin and its role in position effect variegation in Drosophila. Using immunolocalization, we show that HP1 is a constant feature of the telomeres of interphase polytene and mitotic chromosomes. This localization does not require the presence of telomeric retrotransposons, since HP1 is also detected at the ends of terminally deleted chromosomes that lack these elements. Importantly, larvae expressing reduced or mutant versions of HP1 exhibit aberrant chromosome associations and multiple telomeric fusions in neuroblast cells, imaginal disks, and male meiotic cells. Taken together, these results provide evidence that HP1 plays a functional role in mediating normal telomere behavior in Drosophila.


Subject(s)
Chromosomal Proteins, Non-Histone/metabolism , Drosophila melanogaster/genetics , Insect Proteins/metabolism , Telomere/genetics , Anaphase , Animals , Cell Line , Chromatin/genetics , Chromatin/metabolism , Chromobox Protein Homolog 5 , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/immunology , Chromosome Aberrations/genetics , Chromosome Deletion , Drosophila melanogaster/cytology , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Euchromatin , Gene Expression , HSP70 Heat-Shock Proteins/genetics , Heterochromatin/genetics , Heterochromatin/metabolism , In Situ Hybridization, Fluorescence , Insect Proteins/genetics , Interphase , Larva , Male , Meiosis , Metaphase , Mitosis , Neurons , Retroelements/genetics , Spermatocytes , Telomere/metabolism
17.
J Cell Sci ; 111 ( Pt 18): 2753-61, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9718368

ABSTRACT

modulo belongs to the class of Drosophila genes named 'suppressor of position-effect variegation', suggesting the involvement of the encoded protein in chromatin compaction/relaxation processes. Using complementary procedures of cell fractionation, immunolocalisation on mitotic and polytene chromosomes and cross-linking/immunoprecipitation of genomic DNA targets, we have analysed the sub-nuclear distribution of Modulo. While actually associated to condensed chromatin and heterochromatin sites, the protein is also abundantly found at nucleolus. From a comparison of Modulo pattern on chromosomes of different cell types and mutant lines, we propose a model in which the nucleolus balances the Modulo protein available for chromatin compaction and PEV modification. At a molecular level, repetitive elements instead of rDNA constitute Modulo DNA targets, indicating that the protein directly contacts DNA in heterochromatin but not at the nucleolus. Consistent with a role for Modulo in nucleolus activity and protein synthesis capacity, somatic clones homozygous for a null mutation express a cell-autonomous phenotype consisting of growth alteration and short slender bristles, characteristic traits of Minute mutations, which are known to affect ribosome biogenesis. The results provide evidence suggesting that Modulo participates in distinct molecular networks in the nucleolus and heterochromatin and has distinct functions in the two compartments.


Subject(s)
Cell Nucleolus/metabolism , Drosophila/genetics , Drosophila/metabolism , Insect Proteins/genetics , Insect Proteins/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Animals , Binding, Competitive , Chromatin/metabolism , Chromosomes/metabolism , Genes, Insect , Immunohistochemistry , Mitosis , Models, Biological , Phenotype , Repetitive Sequences, Nucleic Acid
18.
J Cell Biol ; 142(2): 307-18, 1998 Jul 27.
Article in English | MEDLINE | ID: mdl-9679132

ABSTRACT

The distinct structural properties of heterochromatin accommodate a diverse group of vital chromosome functions, yet we have only rudimentary molecular details of its structure. A powerful tool in the analyses of its structure in Drosophila has been a group of mutations that reverse the repressive effect of heterochromatin on the expression of a gene placed next to it ectopically. Several genes from this group are known to encode proteins enriched in heterochromatin. The best characterized of these is the heterochromatin-associated protein, HP1. HP1 has no known DNA-binding activity, hence its incorporation into heterochromatin is likely to be dependent upon other proteins. To examine HP1 interacting proteins, we isolated three distinct oligomeric species of HP1 from the cytoplasm of early Drosophila embryos and analyzed their compositions. The two larger oligomers share two properties with the fraction of HP1 that is most tightly associated with the chromatin of interphase nuclei: an underphosphorylated HP1 isoform profile and an association with subunits of the origin recognition complex (ORC). We also found that HP1 localization into heterochromatin is disrupted in mutants for the ORC2 subunit. These findings support a role for the ORC-containing oligomers in localizing HP1 into Drosophila heterochromatin that is strikingly similar to the role of ORC in recruiting the Sir1 protein to silencing nucleation sites in Saccharomyces cerevisiae.


Subject(s)
Chromosomal Proteins, Non-Histone/metabolism , DNA-Binding Proteins/metabolism , Drosophila/metabolism , Insect Proteins/metabolism , Amino Acid Sequence , Animals , Cell Nucleus/metabolism , Chromobox Protein Homolog 5 , Chromosomal Proteins, Non-Histone/chemistry , Chromosomal Proteins, Non-Histone/genetics , Cytoplasm/metabolism , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , Drosophila/embryology , Drosophila/genetics , Drosophila Proteins , Heterochromatin/chemistry , Heterochromatin/genetics , Heterochromatin/metabolism , Insect Proteins/chemistry , Insect Proteins/genetics , Molecular Sequence Data , Mutation , Origin Recognition Complex , Phosphorylation , Protein Binding , Protein Conformation , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism
19.
Chromosoma ; 107(5): 286-92, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9880761

ABSTRACT

Heterochromatin protein 1 (HP1) of Drosophila and its homologs in vertebrates are key components of constitutive heterochromatin. Here we provide cytological evidence for the presence of heterochromatin within a euchromatic chromosome arm by immunolocalization of HP1 to the site of a silenced transgene repeat array. The amount of HP1 associated with arrays in polytene chromosomes is correlated with the array size. Inverted transposons within an array or increased proximity of an array to blocks of naturally occurring heterochromatin may increase transgene silencing without increasing HP1 labeling. Less dense anti-HP1 labeling is found at transposon arrays in which there is no transgene silencing. The results indicate that HP1 targets the chromatin of transposon insertions and binds more densely at a site with repeated sequences susceptible to heterochromatin formation.


Subject(s)
ATP-Binding Cassette Transporters , Chromatin/genetics , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , Drosophila Proteins , Drosophila/genetics , Eye Proteins , Transgenes , Animals , Chromobox Protein Homolog 5 , Chromosome Mapping , DNA Transposable Elements , Genetic Techniques , Heterochromatin/genetics , In Situ Hybridization, Fluorescence , Insect Proteins/genetics , Tandem Repeat Sequences
20.
Ital J Gastroenterol Hepatol ; 29(4): 357-60, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9476191

ABSTRACT

BACKGROUND: Ischaemic colitis is an infrequent, but potentially fatal, complication of abdominal aortic surgery. Its presentation is often underestimated on account of a paucity of symptoms, thus the real incidence of ischaemic colitis may be higher. AIM: To determine the prognostic value and sensitivity of endoscopy, early postoperative endoscopic findings were evaluated. METHODS: Over a period of three years a prospective study was undertaken in a consecutive series of 105 patients (mean age 68.9 years, range 51-85) undergoing routine rectosigmoidoscopy within 72 hours of aortic reconstructive surgery. RESULTS: Colonic ischaemia was found in 12 patients (11.4%); five had endoscopic evidence of mild ischaemic colitis, ulcerations were identified in five and diffuse superficial necrosis in two. Seven of the 12 patients were symptomatic. Laparotomy was never deemed necessary and all patients were successfully treated with a conservative regimen. There were no deaths. Elective reconstruction or urgent procedure did not correlate with the development of colonic ischaemia, nor did duration of aortic cross-clamp time, patency of the inferior mesenteric artery and its possible ligation or reimplantation or patency of the hypogastric arteries. CONCLUSIONS: Rectosigmoidoscopy is effective for early diagnosis of ischaemic colitis. Early endoscopy should be routinely performed only for patients in whom impaired blood flow is suspected on the basis of the intraoperative objective assessment of the colon and in presence of symptoms.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Colitis, Ischemic/diagnosis , Postoperative Complications , Sigmoidoscopy , Vascular Surgical Procedures/adverse effects , Aged , Aged, 80 and over , Colitis, Ischemic/epidemiology , Colitis, Ischemic/etiology , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Postoperative Complications/diagnosis , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Prognosis , Prospective Studies , Reoperation , Sensitivity and Specificity
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