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Biomedical subjects

S Pozzi

Publications and source records attributed to S Pozzi.

At least 19 recordsLinked to original sources

An accessory open reading frame (orf-x) of jaagsiekte sheep retrovirus is conserved between different virus isolates.

Jaagsiekte sheep retrovirus (JSRV) is the etiological agent of a contagious lung tumour of sheep known as sheep pulmonary adenomatosis (syn: ovine pulmonary carcinoma, jaagsiekte). JSRV exhibits a simple genetic organization, characteristic of the type D and type B retroviruses, with the canonical retroviral sequences gag, pro, pol and env encoding the structural proteins of the virion. An additional open reading frame (orf-x), of approximately 500 bp overlapping pol, is present in the only two complete sequences of JSRV published to date. Since very little information is available on the biology of JSRV it is important to establish if orf-x is conserved between different virus isolates. In this study we analysed the orf-x region of JSRV isolates collected from the United Kingdom, Italy, Spain and South Africa. In addition we also analysed the presence of orf-x in JSRV-related endogenous sequences (enJSRVs) present in the sheep genome. Orf-x was highly conserved in all the exogenous isolates (n=10) and in most of the endogenous sequences (n=8). Thus orf-x may be an accessory gene of JSRV and haves a biological function which might be advantageous to JSRV. Phenetic analysis conducted on the complete orf-x nucleotide sequences seems to highlight the presence of three distinct groups statistically well supported by bootstrapping: i) exogenous JSRV sequence from the UK; ii) exogenous JSRV sequences from Southern Europe and iii) the exogenous South African strain plus all the endogenous sequences analyzed and collected from Australia, Italy, UK and South Africa.

Animals↗

Expression and antigenic characterization of recombinant Mycoplasma agalactiae P48 major surface protein.

The gene encoding the P48 major surface lipoprotein of M. agalactiae has been recently characterised. Since its product plays an important role in the immune response of infected animals, in this study we analysed a recombinant P48 expressed in E. coli. Multiple point mutations were introduced by site directed mutagenesis in order to convert four tryptophan TGA codons, which are a typical feature of the mycoplasma genetic code, into the standard TGG. The mutated p48 gene was subcloned into pGex-2T and expressed in fusion with glutathione-S transferase. Following purification steps, P48 was eluted from carrier protein by thrombin digestion and used in Western blot and indirect ELISA using well-characterised sheep sera. Results demonstrate that specific antibodies against P48 are detected 3 weeks after onset of clinical disease and the recombinant P48 is a diagnostically relevant marker of M. agalactiae infection.

Animals↗

Complications and long-term outcome of 80 oncology patients undergoing needle catheter jejunostomy placement for early postoperative enteral feeding.

Some findings suggest that needle catheter jejunostomy (NCJ) is associated with a significant rate of potentially dangerous complications. The purpose of this study was to prospectively evaluate the rate and type of early and late complications associated with NCJ in patients with surgical treatment of upper gastrointestinal malignancy. Eighty patients underwent NCJ implant at the end of their scheduled surgical procedure. Enteral nutrition programme was started on postoperative day 1 in the surgical ICU. NCJ was always removed in the outpatient clinic after hospital discharge. One case of tube blockage has been observed as single short-term complication in this series. No long-term complications have been detected after a mean follow-up of 12 months. Routine use of NCJ in malnourished patients undergoing major surgical procedures on upper gastrointestinal tract is safe and effective.

Adolescent↗

[Secondary glaucoma in Paraguay. Etiology and incidence].

Glaucoma is the third-most-frequent cause of blindness in the world, with a total of 5.2 million blind people as a result of this disease; 80% live in developing countries. In Paraguay, after cataract it is the second-most-frequent-cause. Early detection of the risk factors and groups can help to avoid progress of this disease. Trauma, cataract and infectious uveitis represent special risks for developing secondary glaucoma, which is a more frequent cause of blindness in third-world countries than in industrialized nations. Until now there has been little data regarding the causes, disease course, and options for therapy. Therefore, secondary glaucoma was examined in Paraguay to obtain information on the situation in Latin America. The aim of the study was to explore the causes of secondary glaucoma for programs concerning prevention and therapy. From November 1996 to February 1997 patients with secondary glaucoma were examined at the University Hospital of Asunción, Paraguay. After the clinical examination the secondary glaucomas were classified. Patients with primary glaucoma were included in the same period of time as well in order to get the rate of secondary glaucoma. Altogether 293 patients were examined: 61 with secondary and 232 with primary glaucoma. The causes of secondary glaucoma in 73 eyes were: 20 (27%) with pseudoexfoliation glaucoma, 19 (26%) with post-traumatic glaucoma, 16 (22%) with neovascular glaucoma, 4 (5%) with lens-related glaucoma, 3 (4%) with glaucoma associated with ocular surgery, 2 (3%) with pigmentary and 2 (3%) with corticoid-induced glaucoma. A ratio of 4:1 primary glaucomas to secondary glaucomas was found. The development of special measures for prevention and early therapy is only possible if the causes of this severe disease are explored. The results of this study represent basic information and could help to introduce of prevention programs.

Adolescent↗

HLA-B locus sequence-based typing.

We describe an approach for HLA-B high-resolution typing. A single locus-specific amplification generates a 1-kb fragment useful for direct sequencing. Four internal primers are necessary for exon 2 and 3 cycle-sequencing in both directions. Fluorescent dye-labelled nucleotides are incorporated during cycle-sequencing and reaction products are analyzed in an automated DNA sequencer. At present, software programs allow automatic assignment of exon 2 only; analysis of exon 3 is not automatic. In the future, the development of more sophisticated software will improve allele assignment. The approach described in this work offers a precise and efficient identification of known allele sequences and at the same time can differentiate new alleles. Furthermore, it may be applied as a model for the development of similar molecular typing approaches for other polymorphic HLA loci.

Alleles↗

Totally implantable central venous access ports for high-dose chemotherapy administration and autologous stem cell transplantation: analysis of overall and septic complications in 68 cases using a single type of device.

Sixty-eight patients suffering from breast cancer, ovarian cancer, lymphoma or multiple myeloma were treated with high-dose chemotherapy and autologous stem cell transplantation. They underwent placement of a central venous port via the subclavian vein for delivery of chemotherapy and reinfusion of stem cells. All patients were followed prospectively for device-related and overall complications, comprising a total of 18,213 days in situ (median: 267 days, range: 90-480). One patient experienced a pneumothorax (1.4%) spontaneously resolved, as an acute toxicity. Two patients (2.8%, 0.1 episodes/1000 days of use) were forced to have the port removed due to infection, caused by Streptococcus mitis in one case, while the causative agent was not identified by laboratory tests in the second. The other 66 patients completed the therapeutic programme, including peripheral stem cell reinfusions and supportive care, such as i.v. antibiotics, antiemetics or fluid administration and blood sample collection, without additional complications. In conclusion, the use of totally implantable central venous access ports has resulted in good long-term access to central veins, in spite of the severe neutropenia and increased septic risk of this category of oncology patients.

Adult↗

HLA-A, -B, -C genotyping and expression in human nonlymphoid tumor cell lines.

A combination of molecular genotyping and protein biochemistry methods was used to assess the HLA-A, -B, -C genotyping and expression of six tumor cell lines. Four cell lines had been previously HLA typed by conventional serologic methods. Two could not be typed by serology because deficient in the surface expression of HLA-A, -B, -C molecules. As shown herein, all the 25 alleles carried by the six tested cell lines were typed at the DNA level. In addition, discrepancies between the previous serologic and the present DNA typing results were detected in 9 of the 21 tested serologic specificities. Typing at the protein level by isoelectric focusing and allele-specific monoclonal antibodies confirmed the DNA typing data. Our results exemplify the limits of the serologic typing procedures and demonstrate that molecular methods are highly desirable to conduct functional experiments and identify HLA losses in neoplastic cells at single allele level.

Alleles↗

P48 major surface antigen of Mycoplasma agalactiae is homologous to a malp product of Mycoplasma fermentans and belongs to a selected family of bacterial lipoproteins.

A major surface antigenic lipoprotein of Mycoplasma agalactiae, promptly recognized by the host's immune system, was characterized. The mature product, P48, showed significant similarity and shared conserved amino acid motifs with lipoproteins or predicted lipoproteins from Mycoplasma fermentans, Mycoplasma hyorhinis, relapsing fever Borrelia spp., Bacillus subtilis, and Treponema pallidum.

Amino Acid Motifs↗

Primary cardiac lymphoma. A case report and review.

Primary cardiac lymphoma is classically defined as an extranodal non-Hodgkin's lymphoma exclusively located in the heart and/or pericardium. However, over the last few years, this definition has been extended to include other localizations on condition that these are clearly less important then a cardiac site, that must remain the first, during the illness course, and the most important for its entity. PCL is extremely rare in immunocompetent patients, accounting for 1.3% of all cardiac tumours and 0.5% of all extranodal lymphomas, but it has been encountered with increasing frequency in patients with AIDS or other severe immunodepressive syndromes. PCL is difficult to diagnose, especially during the early stage of the disease, because of its non-specific clinical manifestations, the limited possibility of using non-invasive diagnostic techniques, and difficulties or delays in applying invasive methods. The malignancy of its histotypes and its delicate location are responsible for its rapid and frequently unfavourable evolution. Successful treatment, which is mainly based on anthracycline-containing polychemotherapies, is heavily dependent on an early diagnosis. After a general review of the literature, the authors describe the clinical case of a patient with a PCL that had a secondary central nervous system location, treated with polychemotherapy and autologous peripheral blood stem cell transplantation. Emphasis is placed on the fact that it is more difficult to eradicate the disease from the central nervous system than from the heart.

Echocardiography↗

STK11 mutations in Peutz-Jeghers syndrome and sporadic colon cancer.

A potential tumor suppressor gene, STK11 , encoding a serine threonine kinase, has recently been identified on chromosome 19p13. Germ-line mutations of this gene have been found in patients with Peutz-Jeghers syndrome (PJS). To further investigate the relevance of STK11 mutations in PJS, we analyzed its coding sequence in nine patients and identified two deletions and three missense mutations. Because intestinal carcinomas have been observed to develop in association with PJS, we analyzed tumors from 71 patients for allelic deletions (loss of heterozygosity) and STK11 gene mutations, to elucidate the etiological role of STK11 gene in sporadic colorectal cancer. Loss of heterozygosity, evaluated using the microsatellite D19S886, was observed in 10 of 52 informative cases. No somatic mutations were detected except for a missense alteration in one tumor. Our data indicate the heterogeneity of PJS and the infrequent involvement of the STK11 gene in colorectal cancer.

AMP-Activated Protein Kinase Kinases↗

Totally implantable central venous access ports for long-term chemotherapy. A prospective study analyzing complications and costs of 333 devices with a minimum follow-up of 180 days.

BACKGROUND: A few data are available from analyses of the complications and costs of central venous access ports for chemotherapy. This prospective study deals with the complications and global costs of central venous ports connected to a Groshong catheter for deliverance of long-term chemotherapy. PATIENTS AND METHODS: Patients with a variety of solid neoplastic diseases requiring chemotherapy who were undergoing placement of implantable ports over a 30-month period (1 October 1994 to 31 March 1997) have been prospectively studied. Follow-up continued until the device was removed or the study was closed (30 September 1997); patients with uneventful implant experience and subsequent follow-ups of less than 180 days were not considered for this study. A single port, constructed of titanium and silicone rubber (Dome Port, Bard Inc., Salt Lake City, USA), was used, connected to an 8 F silastic Groshong catheter tubing (Bard Inc., Salt Lake City, USA). Two-hundred ninety-six devices were placed in the operating room under fluoroscopic control even in the patients treated and monitored in a day-hospital setting: 37 of them were in an angiographic suite. A central venous access form was filled in by the operator after the procedure and all ports were followed prospectively for device-related and overall complications. The average purchase cost of the device was obtained from the hospital charges, based on the costs applied during the 30-month period of the study. Insertion and maintenance costs were estimated by obtaining the charges for an average TIAP implant and its subsequent use; the costs of complication management were assessed analytically. The total cost of each device was defined as the purchase cost plus the insertion cost plus the maintenance cost plus the cost of treatment of the complications, if any. The cost of removing the TIAP was also included in the economic analysis when required by the treatment of the complication. RESULTS: Three hundred thirty-three devices, for a total of 79,178 days in situ, were placed in 328 patients. Five patients received second devices after removal of the first. In all cases the follow-up was appropriate (median 237 days, range 180-732). Early complications included 10 pneumothoraxes (3.4%; six tube-thoracostomies were applied, 1.8%) and six revisions for port and/or catheter malfunction (overall early complications = 16, 4.48%). Late complications comprised five instances of catheter rupture and embolization (1.5%, 0.063 episodes/1000 days of use), five of venous thrombosis (1.5%, 0.063 episodes/1000 days of use), one of pocket infection (0.3%, 0.012 episodes/1000 days of use), and eight of port-related bacteremia (2.4%, 0.101 episodes/1000 days of use). The infections were caused by coagulase-negative Staphylococcus aureus (five cases), Bacillus subtilis (one case), Streptococcus lactaceae (one case) and an unknown agent (one case); port removal was necessary in six of eight cases. The total cost per patient treated for a six-month period, consisting of the costs of purchase and implantation, treatment of early and late complications, and of maintenance of the device, is US$1,970. CONCLUSIONS: This study represents the largest published series of patients with totally implantable access ports connected to a Groshong catheter. We have shown that US$2,000 are sufficient to cover six months of chemotherapy in one patient using the most expensive commercially available implantable port. According to the present study, totally implantable access ports connected to a Groshong catheter are associated with high purchase and insertion costs, a low complication rate and low maintenance costs. These data support their increasing use in current oncologic medical practice.

Adolescent↗

Bone marrow transplantation for chronic myeloid leukemia (CML) from unrelated and sibling donors: single center experience.

This is a report on 60 consecutive patients with chronic myeloid leukemia (CML) who received an allogeneic bone marrow transplant (BMT) in this Unit. Donors were HLA-identical siblings (SIB) (n = 36) or unrelated donors (MUD) (n = 24) matched by serology for HLA A and B and by molecular biology for HLA DR. All patients were prepared with cyclophosphamide 120 mg/kg and fractionated total body irradiation 10-12 Gy. GVHD prophylaxis consisted of cyclosporin A (CsA) starting on day -7 and short-course methotrexate. Bone marrow was unmanipulated in all cases. Cytomegalovirus prophylaxis consisted of acyclovir for SIBs and foscarnet for MUDs. When compared to SIB transplants, MUD patients were younger (29 vs 36 years; P = 0.002), had younger donors (31 vs 39; P = 0.001), had a longer interval between diagnosis and BMT (1459 vs 263 days; P < 0.001) and received a smaller number of nucleated cells at transplant (3.3 vs 4.4 x 10(8)/kg; P = 0.003). More MUDs had advanced disease (50 vs 17%, P = 0.005). The median day to 0.5 x 10(9)/l neutrophils was similar in both groups (18 days for SIBs vs 17 days for MUDs; P = 0.06); the median platelet count on days +30, +50, +100 was significantly (P < 0.01) higher in SIB than in MUD patients (122 vs 38, 113 vs 50 and 97 vs 45 x 10(9)/l, respectively). Acute GVHD was scored as absent-mild, moderate, or severe, in 36, 58 and 6% of SIBs vs 25, 42 and 33% in MUD patients (P = 0.01). Chronic GVHD was comparable (P = 0.1). The actuarial risk of CMV antigenemia at 1 year was 60% in both groups. There were six deaths in SIB patients (two leukemia, two infections, one GVHD, one pneumonitis) and four deaths in MUD patients (three acute GVHD and one infection). Fifty patients survive with a median follow-up of 656 days for SIBs and 485 for MUDs. The actuarial 3-year transplant-related mortality is 12% in SIBs and 17% in MUDs (P = 0.5); the actuarial relapse is 18% in SIBs vs 6% in MUDs (P = 0.4) and 3-year survival 78% in SIBs vs 82% in MUDs (P = 0.7). This study suggests that survival of CML patients after marrow transplantation from unrelated or sibling donors is currently similar, provided the former are well matched. The increased incidence of GVHD in MUD patients is possibly compensated by a lower risk of relapse.

Acyclovir↗

Postoperative enteral feeding does not prevent intestinal bacterial translocation, but reduces the rate of pulmonary infections in pigs undergoing total orthotopic small bowel transplantation.

OBJECTIVE: To assess the effects of a non-elemental liquid diet on nutritional state, composition of bowel flora, intestinal translocation, and pulmonary infections after small bowel transplantation in pigs. DESIGN: Prospective randomised experiment. SETTING: Teaching hospital, Italy. MATERIAL: 32 female Large White pigs. INTERVENTIONS: Group 1 (n = 6) underwent small bowel transplantation, were treated with immunosuppression, and fed on commercial chow. Group 2 (n = 6) were treated similarly except that they were fed with an enteral feed through a tube gastrostomy starting on day 4 postoperatively. Group 3 (n = 6) were treated similarly to group 1 except that they had no immunosuppression, and Group 4 (n = 6) underwent orthotopic small bowel autotransplantation; 8 further pigs underwent a sham operation only to act as controls. MAIN OUTCOME MEASURES: Signs of rejection, graft-versus-host-disease, luminal bacterial overgrowth, bacterial translocation, pneumonia, and the pigs' nutritional state. RESULTS: All animals in group 3 showed signs of acute rejection. There was appreciable overgrowth of aerobic and anaerobic bacteria in all three groups after allotransplantation compared with controls. The counts of anaerobic bacteria were significantly lower in group 2 (enterally fed animals) compared with those given free access to commercial chow [mean (SD) 2.81 (1.39) log CFU/cm2 compared with 4.80 (1.65), p = 0.047]. Bacterial translocation developed to a similar degree after autografts and allografts and pneumonia developed in fewer animals after enteral feeding (1/6) than after conventional feeding (5/6) but the difference was not significant (p = 0.08, odds ratio 25.0, 95% confidence interval of odds ratio 1.20 to 521.13). Enterally fed animals also lost less weight than conventionally fed animals [2.32 (1.23) kg compared with 4.53 (1.74), p = 0.016]. CONCLUSIONS: Enteral feeding for up to a month slightly reduced the rate of pneumonia and resulted in a better nutritional state in pigs after small bowel transplantation. It had no effect on luminal bacterial overgrowth or translocation.

Animals↗