Search PubMed⌕ Search

Biomedical subjects

M Gasmi

Publications and source records attributed to M Gasmi.

12 recordsLinked to original sources

Early refeeding after endoscopic biliary or pancreatic sphincterotomy: a randomized prospective study.

BACKGROUND AND STUDY AIMS: Patients who have undergone endoscopic sphincterotomy (ES) are usually left to fast for arbitrary reasons until they are examined on the following day. The aim of this study was to check whether this systematic fasting after ES is actually justified. PATIENTS AND METHODS: A blinded randomized prospective study, involving 146 patients, was carried out from January 1999 to September 2001. All patients undergoing biliary and/or pancreatic endoscopic sphincterotomy during this period were randomly allocated to one of two groups: group 1 patients were re-fed 4 hours after ES, and the group 2 patients were only re-fed 24 hours after the procedure. These two groups were comparable for clinical and procedural data except for stenting. RESULTS: Eight patients in group 1 (11 %) and 26 patients in group 2 (37 %) suffered from abdominal pain which resolved with analgesic drug treatment (P = 0.01). Eight patients in the first group(11 %) and five patients in the second group (7 %) had to be given major opiate analgesics (P = 0.56). Refeeding resulted in abdominal pain in five patients in group 1 and 13 in group 2 (P = 0.04). The serum amylase and lipase levels increased significantly after refeeding in group 1, but lipasemia did not increase significantly in group 2. No significant differences in post-ES complications were observed between the two groups. The mean hospital stay was significantly shorter in group 1 : 2.6 days on average, vs. 3.8 days in group 2 (P = 0.03). CONCLUSIONS: In the absence of any perforation of the digestive tract or immediate severe acute pancreatitis, early refeeding could be helpful to decrease pain and shorten the hospital stay in patients who have undergone endoscopic sphincterotomy.

Amylases↗

Complications of endoscopic sphincterotomy: results from a single tertiary referral center.

BACKGROUND AND STUDY AIMS: Complications of endoscopic sphincterotomy (ES) have been assessed in recent multicenter studies. The aim of this series was to report and identify risk factors for complications of ES at a single tertiary referral center. PATIENTS AND METHODS: Between 1996 and 2000, 1159 consecutive endoscopic retrograde cholangiopancreatographies (ERCP) procedures were performed and their related complications were assessed. A total of 658 patients (57 %) underwent ES. All the clinical, radiological and biological data were carefully recorded within the 30 days following the procedure. Multivariate analysis was performed using a stepwise logistic model. RESULTS: The morbidity rate for ES was 7.7 %, being moderate to severe in 5 %. Morbidity included acute pancreatitis (3.5 %), perforations (1.8 %), sepsis (1.2 %) and bleeding (1.2 %). The 30-day mortality was 0.9 %. In the 1159 ERCP procedures, 231 patients underwent precut papillotomy (20 %) followed by sphincterotomy in 174 cases. Using logistic regression analysis, the risk factors for ES were precut papillotomy (relative risk, RR 2.76), confidence interval, (CI 1.39 - 5.49) and the presence of sphincter of Oddi dysfunction (RR, 7.72, CI 3.2 - 18.4). CONCLUSIONS: In this single-center series, we found a complication rate of ES in about 7 %, comparable to that in multicenter series. Precut papillotomy and sphincter of Oddi dysfunction were the main independent risk factors for ES.

Female↗

FIV vector systems.

Why is feline immunodeficiency virus (FIV) such an appealing candidate for gene therapy vector development? Phylogenetic analysis suggests FIV is only distantly related to the primate lentiviruses, and despite repeated exposure, neither seroconversion nor other detectable evidence of human infection occurs. FIV naturally infects diverse Felidae worldwide, including the domestic cat. Here, the disease progression parallels the immunodeficiency caused by HIV, and for that reason, FIV and the cat provide an excellent model for anti-virals and AIDS vaccine research. Simple genome organization also facilitates vector development and analysis: FIV has only three accessory/regulatory proteins. To overcome FIV's cat-specific tropism, feline vectors are equipped with hybrid LTRs, since the FIV LTR shows low activity in human cells. Recombinant FIV vectors generate titers comparable to other lentiviral systems, are capable of incorporating heterologous envelopes and efficiently transduce dividing and nondividing cells in the presence and absence of the accessory proteins in vitro. Compared to HIV vectors, FIV vector development is still in its infancy, but initial in vivo data in various species and tissues indicate long-term gene expression at therapeutic levels, and thus FIV vectors hold great promise. Future efficacy studies in animal models and primates will determine the FIV vectors' suitability for gene therapy. The design of recombinant FIV vectors incorporates safety features described for primate lentiviral vectors with the benefit that biosafety testing of FIV vectors can occur in the natural host. Currently, FIV vectors are generated in a transient fashion, but the availability of a stable producer system amenable to better characterization and scale-up will considerably increase the potential for use of FIV vectors in the clinic.

Animals↗

Requirements for efficient production and transduction of human immunodeficiency virus type 1-based vectors.

A number of human immunodeficiency type 1 (HIV-1)-based vectors have recently been shown to transduce nondividing cells in vivo as well as in vitro. However, if these vectors are to be considered for eventual clinical use, a major consideration is to reduce the probability of unintended generation of replication-competent virus. This can be achieved by eliminating viral genetic elements involved in the generation of replication-competent virus without impairing vector production. We have designed a system to transiently produce HIV-1-based vectors by using expression plasmids encoding Gag, Pol, and Tat of HIV-1 under the control of the cytomegalovirus immediate-early promoter. Our data show that the best vector yield is achieved in the presence of the Rev/Rev-responsive element (RRE) system. However, the constitutive transport element of Mason-Pfizer monkey virus can substitute for RRE and Rev at least to some extent, whereas the posttranscriptional regulatory element of human hepatitis B virus appeared to be inefficient. In addition, we show that high-titer virus preparations can be obtained in the presence of sodium butyrate, which activates the expression of both the packaging construct and the vector genome. Finally, our results suggest that efficient infectivity of vectors defective in the accessory proteins Vif, Vpr, Vpu, and Nef depends on the nature of the target cells.

Butyric Acid↗

Minimum requirements for efficient transduction of dividing and nondividing cells by feline immunodeficiency virus vectors.

The development of gene delivery vectors based on feline immunodeficiency virus (FIV) is an attractive alternative to vectors based on primate sources for the delivery of genes into humans. To investigate the requirements for efficient transduction of dividing and nondividing cells by vector particles based on FIV, a series of packaging and vector constructs was generated for which viral gene expression was minimized and from which unnecessary cis-acting sequences were deleted. Pseudotyped vector particles produced in 293T cells were used to transduce various target cells, including contact-inhibited human skin fibroblasts and growth-arrested HT1080 cells. FIV vectors in which the U3 promoter was replaced with the cytomegalovirus promoter gave rise to over 50-fold-higher titers than FIV vectors containing the complete FIV 5' long terminal repeat (LTR). Comparison of the transduction efficiencies of vectors containing different portions of the FIV Gag coding region indicates that at least a functional part of the FIV packaging signal (Psi) is located within an area which includes the 5' LTR and the first 350 bp of gag. Transduction efficiencies of vectors prepared without FIV vif and orf2 accessory gene expression did not differ substantially from those of vectors prepared with accessory gene expression in either dividing or nondividing cells. The requirement for FIV rev-RRE was, however, demonstrated by the inefficient production of vector particles in the absence of rev expression. Together, these results demonstrate the efficient transduction of nondividing cells in vitro by a multiply attenuated FIV vector and contribute to an understanding of the minimum requirements for efficient vector production and infectivity. In addition, we describe the ability of an FIV vector to deliver genes in vivo into hamster muscle tissue.

Animals↗

Transfusion transmission of human T-lymphotropic virus type I (HTLV-I) from an asymptomatic blood donor: conservation of LTR U3, env, and tax nucleotide sequences in a recipient with HTLV-I-associated myelopathy.

BACKGROUND: Transfusion of human T-lymphotropic virus type I (HTLV-I) contaminated blood is sometimes linked with the rapid onset of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in immunocompromised recipients. STUDY DESIGN AND METHODS: This study addressed the question of whether HTLV-I variants could emerge in an immunocompromised patient who developed HAM/ TSP after the transfusion of blood from an asymptomatic HTLV-I carrier. Base pairs (n = 2327) of the HTLV-I genome located in the LTR U3 region and parts of the env and tax genes were sequenced and compared to the isolated identified in the asymptomatic blood donor and to well-known ATK-1 and H5 strains. The same analysis was performed on another set of samples from an asymptomatic HTLV-I-positive blood donor and a similar blood recipient. RESULTS: No critical changes in nucleotide sequences were identified in the immunosuppressed HAM/TSP patient when compared with the nucleotide sequences of the corresponding blood donor, the other asymptomatic blood donor and recipient or the ATK-1 and H5 strains. CONCLUSION: Immunosuppression does not seem to favor the emergence of particular nucleotide sequences in the genome located in the LTR U3 region or in parts of the env and tax genes in transfused patients who develop HAM/TSP.

Base Sequence↗

Zidovudine treatment is not associated with HTLV-1 reverse transcriptase gene mutations in HTLV-I/HIV-1 co-infected patients.

Zidovudine treatment of human immunodeficiency virus (HIV) infection induces drug-resistant viral strains harbouring specific amino acid substitutions in the reverse transcriptase (RT). To investigate whether this phenomenon could be observed in the case of human T lymphotropic virus type I (HTLV-I) infection, we analysed the HTLV-I RT proviral gene sequence in five HTLV-I/HIV-1 co-infected patients treated with zidovudine for HIV-1 infection and in one untreated co-infected subject. In the 816 bp of HTLV-I pol gene sequence determined, no particular nucleotide mutation associated with zidovudine therapy could be identified in the treated subjects. Moreover, the dominant HTLV-1 deduced amino acid sequences determined in treated subjects were identical to that from the untreated subject. Our data show that in the co-infected patients already presenting well-defined mutations associated with zidovudine resistance in HIV-1, no mutations were observed in a part of the pol gene coding for the RT activity of HTLV-I.

Acquired Immunodeficiency Syndrome↗

HTLV-I-associated lymphoma presenting as mycosis fungoides in an HTLV-I non-endemic area: a viro-molecular study.

Human T-lymphotropic virus type I (HTLV-I) is endemic in the Caribbean region, south-western Japan and Africa, and is associated with tropical spastic paraparesis and adult T-cell leukaemia/lymphoma (ATLL). Cutaneous forms of ATLL are sometimes indistinguishable from other cutaneous T-cell lymphomas (CTCL). We report a woman living in a non-endemic area for HTLV-I, with no risk factors for viral infection, who developed mycosis fungoides-like ATLL. The findings underline the usefulness of molecular biological techniques in distinguishing between mycosis fungoides and ATLL. We emphasize the need to establish the HTLV-I status of patients with CTCL, even in HTLV-I non-endemic areas, not only to establish a preventive policy in these countries, but also to further our knowledge of the lymphoproliferation spectrum associated with human retroviruses.

Aged↗

Production and characterization of a monoclonal antibody directed against HTLV-1 p19: use in a specific capture enzyme immunoassay.

An enzyme immunoassay (EIA) was developed for detection of Human T-cell Leukemia Virus antigen in culture supernatants and cell lysates. The assay used a mouse monoclonal antibody against HTLV-I p19 major core protein as capture antibody. It has a sensitivity of 1 microgram/ml of HTLV-I protein, 250 pg/ml of purified recombinant p19 and detected p19 in an 10(-2) diluted supernatant of MT2 infected cell and in a 100 MT2 cells lysate (10(6) cells taken at day 7 of culture). The assay enable us to discriminate between HTLV-I and HTLV-II antigens and is reproducibly negative for supernatants and cell lysates of uninfected cells and of HIV-1 infected cells. The assay was found to be more specific and 10 times more sensitive than the reverse transcriptase (RT) assay, and the EIA test became positive three days earlier than RT assay for the HTLV-I cell lines supernatants.

Animals↗