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Biomedical subjects

A Amar

Publications and source records attributed to A Amar.

At least 37 records · Page 2Linked to original sources
PubMed1996

Predominant 45,X,--Y karyotype in donor cells after allogeneic BMT: cytogenetic and molecular analysis.

We describe two women; one (patient 1) with the diagnosis of acute myeloblastic leukemia (AML), the second (patient 2) with myelodysplastic syndrome (MDS). Both patients underwent allogeneic bone marrow transplantation (BMT), from their HLA-matched brothers. Cytogenetic analysis after the BMT revealed a chromosomal mosaicism in both patients, with the karyotype 46,XX/45,X with no sign of the Y chromosome. The origin of the clone with monosomy X was determined using cytogenetic analysis including heteromorphism and segregation of DNA polymorphic markers. The results led us to the conclusion that in both patients the origin of the 45,X clone was that of the donors. Patient 1 had MDS-like syndrome after the BMT and was stabilized in the chimeric state; to date she is doing well. Patient II also had MDS. However, in her case, it was her primary disease. The graft in patient II was rejected and she died 6 months after BMT.

Adult↗
PubMed1996

Second transplantation using allogeneic peripheral blood stem cells in a beta-thalassaemia major patient featuring stable mixed chimaerism.

Allogeneic bone marrow transplantation (BMT) for beta-thalassaemia major carries the risks of disease recurrence due to residual thalassaemic stem cells or true immune-mediated rejection. We report a thalassaemic patient who displayed stable mixed chimaerism with only 5% donor-derived cells for about 5 years after BMT. Displacement of host cells was accomplished by ambulatory non-myeloablative conditioning and allogeneic G-CSF mobilized peripheral blood stem cell transplantation from the same donor, resulting in full reconstitution. Patients featuring stable mixed chimaerism after BMT may benefit from allogeneic cell therapy with immunocompetent lymphocytes and stem cells, whilst avoiding supralethal conditioning.

Bone Marrow Transplantation↗
PubMed1996

[Choledochoduodenal fistula: an unusual complication of duodenal ulcer].

We report a case of choledochoduodenal fistula in a patient with a duodenal ulcer and poor compliance to treatment. The fistula tract was demonstrated on a plain abdominal X-ray (presence of air in the biliary tract), and was confirmed by a fistulography from the site of the ulcer (opacification of the bile duct). A Finsterer type 2/3 gastrectomy was performed in this patient, leading to the treatment of the ulcer and disappearance of the fistula following a gastrojejunal shunt of the duodenum. Clinical outcome was excellent.

Cholecystectomy↗
PubMed1996

[Treatment of rectal prolapse with elastic circling of the anus: Perspectives of utilization].

The Thiersch technique for treatment of rectal prolapsus has been largely abandoned because the metallic or non-resorbable wire is poorly tolerated and non-extensible. Silastic can fulfil these requirements and was used in 11 patients, including two who underwent reoperations. Good results were obtained in 9. This technique is simple and can be proposed when the general status of the patient does not allow surgical cure of the prolapsus.

Aged↗
PubMed1996

[Adenoma of the choledochus].

Two patients with signs of an obstructed main bile duct underwent surgery. Choleductectomy was performed followed by Mirizzi exploration. Extemporaneous pathology examination of the intra-ductal tissue revealed benign adenoma of the main bile duct. Resection of the main bile duct with hepato-duodenal anastomosis was performed in the first patient and resection with end-to-end anastomosis in the second.

Adenoma↗
PubMed1995

Immunolocalization of bone matrix macromolecules in human tissues regenerated from periodontal defects treated with expanded polytetrafluoroethylene membranes.

Guided tissue regeneration (GTR) is a concept that evolved from the development of membrane barrier techniques which allow the repopulation of periodontal wounds by desirable cells, resulting in a so-called new attachment apparatus. To understand the biological mechanisms involved in membrane barrier-led periodontal healing, the histological localization of macromolecules phenotypical of bone and cementum formation was investigated in regenerating human periodontal tissues harvested after healing by placing barriers on teeth untreatable except by extraction. Using immunolocalization techniques, frozen sections of soft tissues and hard tissues under GTR barriers were stained with antibodies to osteonectin (LB-BON-II) and bone sialoprotein (BSP) (LF-6); alkaline phosphatase (AP) was detected histochemically. Frozen sections of regenerating periodontal tissue demonstrated the presence of spindle-shaped, fibroblast-like cells entrapped in a dense fibrillar extracellular matrix. Rounded cells aggregated to form nodules heavily stained by the Alcian blue method, indicating the presence of proteoglycans and strongly resembling those noted in hard-tissue sections. At the electron-microscopic level, the cytoplasm of the elongated cells had numerous cisternae of endoplasmic reticulum and Golgi saccules, indicating metabolic activity. Striated collagen fibres were scattered throughout the field of the sections. AP-stained soft-tissue sections demonstrated the presence cell-bound and extracellular AP. Osteonectin antibody staining confirmed the presence of this macromolecule in the extracellular matrix, particularly in the area of the cellular nodules. The dense network of connective tissue fibres was also stained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

HLA class II analysis in Jewish Israeli narcoleptic patients.

HLA class II was investigated in eight Jewish narcoleptic patients, representing the total of such patients known in Israel at present, and in three patients suffering from sleep disturbances other than narcolepsy. All (11 out of 11) patients carried the serologic specificities DR2, DQ6 (DQ1). At the DNA level, all narcoleptics were found to be DRB1*1501, DQA1*0102, DQB1*0602 which indicates that the susceptibility gene may be located within the HLA class II region, DR, and/or DQ. As for the nonnarcoleptic patients with idiopathic hypersomnia, they carried different alleles of DR2 and DQ6, namely DRB1*1502, DQA1*0103, DQB1*0601. This study confirms that the incidence of narcolepsy in Israel is extremely low and that HLA class II genes or a gene(s) tightly linked to them are involved in the disease.

Alleles↗
PubMed1995

[Spontaneous rupture of the esophagus diagnosed late. Recovery by directed fistulization].

Spontaneous rupture of the oesophagus is uncommon and is difficult to diagnose in the early stage. Clinical signs are lacking or incomplete, causing a delay in diagnosis and therapy which requires both intensive medical care and surgery. The surgical procedure depends on the time lapse to diagnosis. We report a case diagnosed 16 days after rupture in which directed fistulization led to complete healing.

Aged↗
PubMed1995

The putative role of HLA-C recognition in graft versus host disease (GVHD) and graft rejection after unrelated bone marrow transplantation (BMT).

We assessed cytotoxic activity of large granular lymphocytes (LGLs) derived from 10 patients transplanted from molecular HLA-C mismatched (5) and matched (5) unrelated donors and compared it to the cytotoxic activity of 10 patients transplanted from HLA-identical siblings. In addition, we correlated clinical outcome with the level of molecular HLA-C disparity in a cohort of 22 patients who underwent unrelated BMT. Cells obtained from patients transplanted (related or unrelated) from fully matched donors did not generate allospecific lysis of patient (pre-BMT) or donor PHA blasts. Five of nine patients who received BMT from HLA-C mismatched unrelated donors developed > grade II graft-vs.-host disease (GVHD), and four developed graft rejection. Cells derived from three of three patients with GVHD lysed patients' pre-BMT PHA blasts. In the patients with GVHD grade III-IV, cytotoxicity was higher (60-70%) than in the patient with grade II GVHD (20%) (p < 0.05). Cytotoxic cells derived from one patient who rejected his graft lysed donor PHA blasts. In one remaining patient who had graft rejection followed by autologous rescue, no in vitro allospecificity was observed. In summary, cytotoxic cells from patients transplanted with marrow mismatched at locus C demonstrated in vitro cytolysis of PHA blasts, and this phenomenon showed positive correlation with the clinical outcome of the BMT. These findings may indicate specific allorecognition. A mismatch at locus C leading to alloreactivity should be considered a risk factor in determining an appropriate match for allogeneic BMT, especially when the donor is unrelated.

Adolescent↗
PubMed1994

Development of a non-selecting, non-perturbing method to study human brain tumor cell invasion in murine brain.

The infiltrative nature of glial and some meningeal neoplasms is responsible for the failure of surgical removal and high recurrence rate of these tumors. Modeling of this process in vitro and in vivo will lead to a better understanding of the pathophysiology of this process and identify targets for novel therapy directed towards this phenotype. We present the results of the development and refinement of two model systems of tumor invasion: one in vitro barrier assay using the basement membrane extract Matrigel, and one in vivo where molecular detection of tumor cells allows single cell discrimination by in situ hybridization histochemistry. These techniques have strong correlations which validate their utility as measures of nervous system tumor invasion.

Animals↗
PubMed1993

The treatment of 783 keloid scars by iridium 192 interstitial irradiation after surgical excision.

PURPOSE: the aim of this study is to confirm the effectiveness of irradiation associated with surgery in the treatment of keloids, to precise the factors favoring the recurrence of these keloids, and to evaluate the risk of recurrence, according to their initial distinctive features. METHODS AND MATERIALS: between 1977 and 1988, 544 patients, with a total of 855 keloids, were treated by interstitial radiotherapy immediately following total excision. RESULTS: recurrence rate is 21%, as against 50 to 80% for surgery alone, according to most authors. This recurrence rate is about the same as for external radiotherapy, but we prefer our method for practical reasons (cost, equipment, radiobiology, technique). Ninety percent of recurrences occurred in the year following therapy, which proves that a follow-up time of at least 12 months is needed for a study of keloids. In our experience, the keloids that are the most likely to recur are the largest and those giving rise to most symptoms. Bruising and loosened stitches, but in particular infection during therapy, largely favor a recurrence. In our series, the symptoms disappeared or were much improved in 80% of cases, and the cosmetic result was judged good by 75% of the patients. CONCLUSION: the results of this study proves the effectiveness of the method linking surgical excision and Iridium 192 interstitial irradiation and shows the importance of the sterile conditions of the treatment.

Adolescent↗
PubMed1993

Invasive squamous cell carcinoma of the cervix: is HLA-DQ a disease marker in Jewish patients?

HLA class I and class II were investigated in 30 Israeli patients with invasive squamous cell carcinoma of the cervix and compared to healthy controls. None of the studied serological specificities were found to be associated with the disease. Genomic DNA from the patients was amplified by PCR, dot-blotted and hybridized with sequence specific oligonucleotide probes defining the known DQA1 and DQB1 allelic variants. Fifteen out of the 30 patients tested (50%) were found to carry the DQA1*0501 allelic variant, which is common in the local healthy population (67%). DQB1*0302 was found in eight out of 30 patients (27%) while this allele was present in 17% of the healthy population, a difference which is not statistically significant. Our data indicate that there is no apparent association between invasive squamous cell carcinoma of the cervix and the HLA antigens and alleles studied including the alleles of the DQA and DQB loci in the Israeli population. Our findings indicate that MHC genes could not be useful in the diagnosis of squamous cell carcinoma of the cervix.

Alleles↗