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J L Gala

Publications and source records attributed to J L Gala.

At least 37 records · Page 2Linked to original sources
PubMed1998

The prothrombin gene G20210A variant in an unselected thromboembolic population. A Belgian prospective clinical study.

The presence of the 20210A allele of the prothrombin gene has recently been shown to be a risk factor of venous thromboembolism, probably mediated through increased prothrombin levels. The aim of the study was to determine the frequency of the prothrombin 20210A allele in 193 consecutive unselected patients with venous thromboembolism and 100 healthy controls and to analyze the clinical profile associated with this new inherited thrombophilic factor. In agreement with previous reports, we found a frequency of 7.3% of heterozygous carriers of the 20210A allele among patients and 1% among controls. We confirm that plasma prothrombin levels are more elevated in the individuals bearing the prothrombin 20210A allele compared with those who do not. We did not find any relationship between the presence of the prothrombin 20210A allele and either a family history of thromboembolism, the rate of recurrences or the age at disease onset. However, the co-inheritance in the same individual of both prothrombin 20210A allele and factor V Leiden was associated with a significantly lower age at disease onset suggesting a synergistic contribution of both abnormalities.

Adult↗
PubMed1998

Rapid and specific molecular identification of methicillin-resistant Staphylococcus aureus in endotracheal aspirates from mechanically ventilated patients.

Multiplex amplification of femA and mecA genetic determinants allowed an early and rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) in endotracheal aspirates of mechanically ventilated patients. femA and/or mecA amplification and bacteriological results were concordant in 57 of 60 samples. In all three discrepant cases, complementary bacteriological tests confirmed the presence of MRSA first identified by molecular analysis. These results underline the value and rapidity of this molecular diagnosis for MRSA infection and control surveillance in intensive care units. Rapid MRSA detection is expected to have a significant clinical impact not only on patient outcome but also on the costs for isolation and treatment.

Bacterial Proteins↗
PubMed1998

Expression of prostate-specific antigen and prostate-specific membrane antigen transcripts in blood cells: implications for the detection of hematogenous prostate cells and standardization.

Circulating prostate cells can be detected in cancer patients by using reverse transcriptase-PCR (RT-PCR) assay for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) mRNA. A quality-control study involving a conventional RT-PCR assay was performed and, surprisingly, detected both transcripts in many negative control cell lines and in normal blood samples. The existence of an illegitimate transcription of the PSA and PSM genes was evidenced by sequence analysis of several PSM and PSA-PCR products. Sequencing indeed demonstrated the presence of a PSA or PSM polymorphism in some but not all the cell lines and patient samples, as well as a heterozygous mutation (G to A; Asp to Asn) in the Jurkat cell line. Moreover, the amount of PSA transcript in MCF-7, a PSA-negative breast line, increased after incubation with cycloheximide. Interestingly, the frequency of positivity was as high as 12% in male samples if only tested once, but dropped to 3% upon multiple testing of the same cDNA. This highlights the stochastic effects in RT-PCR results at high sensitivity, hence the importance of repetitive testing in clinical samples. Decreasing the number of cycles avoided the amplification of illegitimate transcripts but also affected the limit of detection, as evidenced with PSA and PSM cDNA containing plasmids, mixing of LNCap with normal blood samples, and the PSA-PSM-negative K562 cell line. The current data raise the need for a multicentric standardization of the RT-PCR methodology used to amplify PSA and PSM transcripts.

Adult↗
PubMed1998

About two cases of Mycobacterium simiae infection in AIDS: review of the pathogenicity.

Mycobacterium simiae is an ubiquitous species rarely involved as a cause of human infection. Its pathogenicity remains therefore unclear and controversial. Disseminated infections with M. simiae occur rarely and only 7 cases have been reported in patients with acquired immunodeficiency syndrome (AIDS). At least, two were mixed infections caused by M. simiae and M. avium-intracellulare. We report the case of two AIDS patients presenting with pure M. simiae infections: one was a disseminated infection and the other a pulmonary infection. Epidemiology and pathogenicity of M. simiae in pulmonary, extra-pulmonary and disseminated infections are reviewed.

AIDS-Related Opportunistic Infections↗
PubMed1998

Detection of intracellular antigens by flow cytometry: comparison of two chemical methods and microwave heating.

Detection of intracellular antigens by flow cytometry requires effective fixation and permeabilization of the cell membrane. This study compares three fixation/permeabilization techniques: two commercial chemical reagents, the ORTHOPermeaFix (OPF) and the FIX&PERM Cell Permeabilization Kit (F&P), and a novel method based on microwave heating (MWH). They have been applied to the detection of two nuclear (p53 and rb/p105) and two cytoplasmic (bcl-2 and mdr-1/gp-170) antigens, using positive- and negative-control cell lines and peripheral blood mononuclear cells. Western blotting was performed as a control of protein expression. For the four antigens assessed, cellular morphology, discrimination between intact cells and debris, percentage of positive cells, and mean fluorescence intensity were examined. For this last parameter, the assessment of the MWH technique was performed using SD and a graphical approach inspired by the concepts described by Bland and Altman (Lancet 1986;346: 1085-7) as well as Petersen et al. (Clin Chem 1997;43: 2039-46). The statistical analysis shows that MWH is comparable to the commercial methods and that its reproducibility is also equivalent to OPF and F&P. As assessed for some of the most clinically relevant intracytoplasmic and intranuclear antigens, the MWH method appears to be a valuable and inexpensive alternative. It is worth noting that, unlike commercial reagents, MWH altered surface antigens. Interestingly, this feature, which would prevent cell selection on the basis of combined membrane and intracellular epitopes, is associated with a decrease of nonspecific background fluorescence.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Beta-thalassaemia in indigenous Belgians: an update.

Beta-thalassaemia, a widespread autosomal recessive disorder, occurs sporadically in Northern and Western European countries. Molecular analysis of the beta-globin gene has been carried out in 30 members of 15 unrelated indigenous Belgian families which presented with non sideropenic hypochromic and microcytic anaemia. For all of them, extensive search failed to find an ancestor at risk for the disease. The beta-globin genes were first screened for frequent beta-thalassemic mutations by dot-blot hybridization with specific radiolabeled oligonucleotide probes. Direct automated fluorescence-based DNA sequencing and, in one case, Southern blotting were also used. All the 30 patients were found to be heterozygous for a beta-thalassemic mutation. Eight different mutations were identified. Among these, four are commonly found in the Mediterraneans: codon 8 (-AA), IVS-I-1 (G-->A), IVS-1-6 (T-->C) and codon 39 (C-->T); three have occasionally been reported: initiation codon (T-->C) and codon 35 (C-->A) and a rare deletion of 12.6 kb which removes all the beta-globin gene and its flanking regions. A new mutation, a -CC deletion at codon 38/39 was found in one family. These results both at the biological and molecular level show that beta-thalassaemia exist in indigenous Belgian families with no known ancestor a risk for the disease. They also show that clinicians and biologists should keep in mind the existence of beta-thalassaemia in indigenous Belgian families when investigating hypochromic and microcytic anaemia in patients whom the past familial history does not evocate a risk for the disease.

Adenine↗
PubMed1997

HIV-1 detection by nested PCR and viral culture in fresh or cryopreserved postmortem skin: potential implications for skin handling and allografting.

AIMS: To date, the risk relating to the handling or allografting of human immunodeficiency virus type 1 (HIV-1) infected postmortem skin remains hypothetical. While blood screening for HIV antibodies is still the key safety procedure to detect HIV infected cadavers, false negative results are a concern. Conversely, false positive results may hamper the collection of skin allografts. Accordingly, viral culture was used to clarify skin infectivity and the nested polymerase chain reaction (PCR) was used to assess the reliability of skin PCR testing. METHODS: Viral culture and nested PCR performed with gag and pol specific primers were investigated in cadaveric skin and blood from 12 HIV-1 infected patients. Samples were collected repeatedly between one and five days in seven patients. In most cases, analyses were performed on triplicate skin samples: fresh (n = 26); cryopreserved in 5% dimethylsulphoxide (n = 21), or cryopreserved in 30% glycerol (n = 26). RESULTS: HIV was isolated in two of 26 cultures of fresh skin specimens (8%), seven of 47 cryopreserved skin specimens (15%), and eight of 26 blood specimens (31%). The nested PCR detected HIV-1 in all skin samples (n = 73), regardless of the postmortem interval or cryopreservation. In blood, a positive signal was found in eight of 12 patients but two of them had discordant results on successive samples. CONCLUSIONS: These data suggest that nested PCR on postmortem skin samples can detect HIV more reliably than on blood. They also demonstrate the potential viral infectivity of fresh or stored skin postmortem samples in HIV infected patients. They underscore the need for caution during the handling of skin tissue from HIV infected cadavers and confirm the potential risk related to accidental allografting of HIV contaminated skin.

Acquired Immunodeficiency Syndrome↗
PubMed1997

A panel of antibodies for the immunostaining of Bouin's fixed bone marrow trephine biopsies.

AIMS: To assess a panel of antibodies on Bouin's fixed bone marrow trephine (BMT) biopsies. These biopsies are widely used in routine diagnosis of various haematological malignancies and may be the sole material available in many centres; however, information regarding the immunostaining of this material is lacking. METHODS: Biopsies were taken from 72 patients presenting with various haematological malignancies (leukaemia, 38; lymphoma, 14; multiple myeloma, 20). A panel of antibodies was assessed on Bouin's fixed BMT biopsies by the alkaline phosphatase-antialkaline phosphatase method. RESULTS: Three B (MB2, LN-2, Ki-B5) and two T cell lineage antibodies (UCHL-1, CD3-r) reliably identified lymphoid cells, while MPO-r, Leu-M1/CD15, and KP-1/CD68 recognised cells from the myeloid or histiocytic/macrophage series. Reed-Sternberg cells were stained by LN-2, Leu-M1, and CD30. Antibodies specific for plasma cells (VS38) and hairy cells (DBA.44) gave a variable pattern of staining. Among the proliferation markers, proliferative cell nuclear antigen but not Ki-67 related antibodies were effective. CONCLUSION: This study presents a panel of antibodies with reactivity not restricted to common fixatives that are also suitable for Bouin's fixed BMT biopsies.

Antibodies↗
PubMed1996

Beta-thalassaemia in indigenous Belgian families: identification of a novel mutation.

The molecular basis of beta-thalassemia was investigated at the DNA level in 28 Belgians from 14 unrelated families. All the patients were heterozygous for beta-thalassaemia. Seven different mutations were identified using a combination of dot-blot hybridization with allele-specific oligonucleotide probes and direct automated fluorescence-based DNA sequencing. Among these mutations, four are commonly found in the Mediterraneans - codon 8 (-AA), IVS-I-1 (G --> A), IVS-I-6 (T --> C) and codon 39 (C --> T)-and two have occasionally been reported-initiation codon (T --> C) and codon 35 (C --> A). The last mutation, a -CC deletion at codons 38/39, appears to be a novel mutation and can routinely be investigated by AvaII restriction on amplified DNA. We report our findings, discuss the diversity of the mutations found in Belgium and show the usefulness of direct DNA sequencing in a population in which the molecular defects of beta-thalassaemia have yet to be characterized and in which screening is hampered by the wide range of potential mutations.

Belgium↗
PubMed1995

[Nonketotic hyperglycemic coma induced by somatostatin in an AIDS patient].

A 33-year-old woman with AIDS was treated with somatostatin (continuous infusion 6 mg/day) for intractable diarrhoea. Improvement was insufficient and the dose was increased to 12 mg/day 5 days later. Hyperosmolar non-ketotic coma occurred two days later (blood glucose 53 mmol/l, bicarbonate 8 mmol/l, pH of arterial blood 7.2). Search for urinary ketones was negative. Klebsiella pneumonia was isolated in the urine sample. Somatostatin was withdrawn and the patient improved with parenteral nutrition and intravenous insulin. Glucose tolerance was verified after recovery and was normal. Somatostatin is known to impair glucose tolerance and as shown in this case should also be recognized as a cause of hyperosmolar non-ketotic coma. Increasing use of somatostatin, particularly in HIV patients often given other hyperglycaemia inducing drugs such as didanosine, pentamidine, dapsone, and phenytoin should be accompanied with careful monitoring of blood glucose levels.

AIDS-Related Opportunistic Infections↗
PubMed1995

Specific detection of methicillin-resistant Staphylococcus species by multiplex PCR.

In Staphylococcus aureus, mecA and femA are the genetic determinants of methicillin resistance. By using a multiplex PCR strategy, 310- and 686-bp regions of the mecA and femA genes, respectively, were coamplified to identify susceptible (lacking mecA) and resistant (mecA+) staphylococci and to differentiate S. aureus (femA+) from coagulase-negative staphylococci (lacking femA). A third staphylococcal genomic sequence, corresponding to IS431 and spanning 444 bp, was used as a PCR control. One hundred sixty-five staphylococcal strains were tested. All 72 methicillin-resistant strains were found to be mecA+, and 92 of the 93 susceptible isolates lacked mecA. Only one coagulase-negative Staphylococcus isolate carrying the mecA gene was highly susceptible to oxacillin. The femA determinant was a unique feature of S. aureus; it was found in 100% of the S. aureus strains tested but was undetectable in all of the coagulase-negative staphylococci tested. The possibility of directly detecting the mecA and femA genes in blood samples was also investigated. After two amplification steps, a sensitivity of 50 microorganisms per ml of freshly collected spiked blood was achieved. In conclusion, coamplification of mecA and femA determinants proved to be very reliable both for rapid detection of methicillin resistance and differential diagnosis between S. aureus and other staphylococci. This technique, which can be successfully performed with blood samples, could be a useful tool in the diagnosis and treatment monitoring of staphylococcal infections.

Bacterial Proteins↗
PubMed1995

P-glycoprotein positive, drug resistant invasive lymphoepithelial thymoma: treatment response to chemotherapy with cyclosporin and quinine.

A case of invasive drug resistant thymoma, expressing P-glycoprotein, which showed noticeable clinical response to chemotherapy and the multidrug resistance modulating agents cyclosporin and quinine is reported. A 46 year old man presented with severe left shoulder pain and a diagnosis of invasive lymphoepithelial thymoma was made following chest x ray and a computed tomography scan. The patient underwent extensive chemotherapy without resolution of the tumour. More than 90% of the malignant epithelial cells were strongly positive for P-glycoprotein and based on this observation, cyclosporin and quinine were added to the chemotherapy regimen. The mediastinal mass completely resolved and the size of the pleural metastasis decreased substantially. The patient, however, died of an intercurrent infection. This case report highlights the feasibility and efficacy of using cyclosporin and quinine in combination with VAD chemotherapy in the treatment of invasive thymoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

2-Chlorodeoxyadenosine (CdA) for patients with previously untreated chronic lymphocytic leukemia (CLL).

The encouraging therapeutic results attained with the purine analogue CdA in patients with previously treated CLL prompted us to assess its potential in untreated CLL patients. Nineteen patients, 13 males and six females, median age 65 years (range 27-75), with previously untreated CLL were given monthly courses of CdA, 0.12 mg/kg/day as 2-h i.v. infusions for 5 days, until maximum response or excessive toxicity. Five patients with Binet's stage A, 10 with stage B and four with stage C CLL entered the study. After a median of five courses of CdA (range 1-9) nine complete responses (CR = 47%, CI: 24-69%), five partial responses (PR = 26%, CI: 7-46%) and five failures (= 26%, CI: 7-46%) were recorded. In five complete responders and in one partial responder cytofluorometric analysis of blood and/or bone marrow failed to demonstrate a residual clonal B cell population. A search for residual disease by PCR technology and by immunostaining of bone marrow biopsies however disclosed residual leukemic cells in these six cases. Adverse reactions included fever of unknown origin (n = 3), pneumonia (n = 2), herpes simplex infection, herpes zoster, an anal abscess, a cutaneous rash, autoimmune hemolysis and mental disturbance (one patient each). In this small cohort, neither age, stage, blood counts, cytogenetics or pattern of bone marrow infiltration at inclusion were predictive for response. From these preliminary data, we conclude that CdA has remarkable short-term efficacy in patients with previously untreated CLL. However, toxicity is not negligible and long-term benefit from therapy with CdA still has to be established.

Adult↗
PubMed1994

High expression of bcl-2 is the rule in acute lymphoblastic leukemia, except in Burkitt subtype at presentation, and is not correlated with the prognosis.

Bcl-2 expression and its prognostic value were evaluated using the APAAP technique in 40 ALL patients. Because of a possible synergy between c-myc and bcl-2 proteins in cell lines, we compared 40 ALL of either T or B lineage with seven Burkitt's ALL or sporadic Burkitt's lymphomas (BL). We found the same high expression of bcl-2 in adult (Ad) and childhood (Ch) malignancies examined at presentation, regardless of the T or B phenotype. No bcl-2 expression was detectable in BL cases, except for two investigated at relapse. Bcl-2 staining intensity was also not related to the stage of blast differentiation, except in Ad T-ALL, or to the relapse rate. Ki-67, a marker of proliferation, was used to investigate the possible correlation between bcl-2 expression and the proliferative activity. An inverse correlation was found only in BL at presentation. We confirm that bcl-2 expression is the rule in ALL, regardless of the immunophenotypic characteristics at presentation, and that high expression is not correlated with a bad prognosis. Sporadic BL may represent a particular type of tumor, with bcl-2 expression in relapse, but not at presentation.

Adolescent↗
PubMed1994

Specificity and sensitivity of immunocytochemistry for detecting P-glycoprotein in haematological malignancies.

AIMS: To determine the optimal working conditions of the alkaline phosphatase-antialkaline phosphatase (APAAP) method to establish a specific and sensitive assay for the detection of low numbers of MDR positive cells in patients with hematological malignancies. METHODS: Three monoclonal antibodies (C-219, JSB-1, MRK-16) were used for the detection of P-glycoprotein (P-gp) in cell lines and in samples from 43 patients with haematological malignancies. The results of the APAAP method were compared with western blotting for specificity and sensitivity. RESULTS: Excellent correlation was obtained between optimised APAAP and western blotting, except in the case of multiple myeloma. JSB-1 seemed to be the more useful monoclonal antibody for the APAAP which was more sensitive than western blotting in its ability to detect single P-gp positive cells. CONCLUSIONS: Methods for P-gp detection, as defined by multidrug resistant (MDR) cell lines, are not necessarily optimal and specific for clinical samples and may lead to higher false positive and negative results, according to the conditions and the monoclonal antibodies used.

ATP Binding Cassette Transporter, Subfamily B, Mem↗