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Biomedical subjects

F Reyes

Publications and source records attributed to F Reyes.

At least 73 records · Page 4Linked to original sources
PubMed1993

Autologous hematopoietic stem cell transplantation in intermediate and high grade non-Hodgkin's lymphoma: a review.

High dose therapy with or without hematopoietic stem cell rescue has been widely used in the past decade for treating aggressive Non-Hodgkin's lymphoma. Recent data in high and intermediate grade lymphoma were reviewed. Evidence that dose intensity is a critical factor for remission in poor prognosis lymphoma has been accumulated, although the impact on survival has not been clearly established through randomized studies. Intensive treatment with autologous bone marrow transplantation (ABMT) have been reported in more than 1,000 relapsing patients in non randomized trials. For those who are still sensitive to salvage chemotherapy, at 5 years a 40% probability of disease free survival has been uniformly noted. ABMT is accepted by most centers as the treatment of choice for relapsing lymphoma. Consequently, very few randomized studies testing ABMT vs. conventional chemotherapy such as the PARMA protocol are in progress. In patients achieving complete remission, ABMT has been proposed for consolidation in a group of lymphoma sharing adverse prognostic factors with a high risk of relapse. Results from pilot studies were encouraging. However, interim analysis of the large randomized trial LNH87, did not show at the present time an advantage for ABMT performed after CR when compared to conventional chemotherapy. Such a strategy should be only proposed in prospective studies. For patients who did not achieve CR after conventional treatment, but who are still sensitive to chemotherapy, ABMT may improve the results. Pilot studies as well as recent randomized study are in support of this approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Agents↗
PubMed1993

Prognostic significance of received relative dose intensity in non-Hodgkin's lymphoma patients: application to LNH-87 protocol. The GELA. (Groupe d'Etude des Lymphomes de l'Adulte).

BACKGROUND: To evaluate the effects of chemotherapy dose intensity (DI) on outcome in patients with aggressive lymphoma, the received relative DI (received RDI) is usually calculated using Hryniuk's model. We applied this model to a selected patient subgroup included in the LNH87 protocol (LNH87-2 protocol), who had been treated with the ACVB induction regimen. PATIENTS AND METHODS: Patients aged < 55 who had at least one of the following prognostic factors: performance status (PS) > or = 2, number of extranodal sites > or = 2, tumor burden > or = 10 cm, bone marrow or central nervous system involvement, and Burkitt's or lymphoblastic histologic subtype, were included in this study. Actual DI was calculated using the definition of DI as mg/m2/week previously described by Hryniuk. RESULTS: Eighty-seven of the 311 patients included in the study (28%) presented a RDI below 70% of the theoretical DI. We demonstrated a decreased response rate (65% vs. 79%, p = 0.01) and shorter overall 2-year survival (61% vs. 72%, p = 0.02) in patients receiving a DI < 70%. This difference was still significant when the multiparametric analysis was used (p = 0.004). CONCLUSION: Results obtained when this model was applied to aggressive lymphoma patients included in the LNH-87 protocol led to the demonstration of a strong relationship between received RDI and survival.

Adult↗
PubMed1993

Detection of multiple myeloma involving the spine: efficacy of fat-suppression and contrast-enhanced MR imaging.

OBJECTIVE: To determine the efficacy of fat-suppressed sequences and contrast-enhanced MR imaging for the detection of focal spinal lesions caused by multiple myeloma, we obtained MR images in 32 patients with newly diagnosed myeloma who had back pain. SUBJECTS AND METHODS: All patients had biopsy-proved myeloma and had MR imaging at the painful level of the spine. Spin-echo T1-weighted, T2-weighted, and short TI inversion-recovery (STIR) images; dynamic ultrafast low-angle shot (turbo-FLASH) images after IV injection of a bolus of paramagnetic contrast material; and contrast-enhanced T1-weighted images were obtained. We qualitatively compared the signal intensities and contrast enhancement of focal lesions with those of the surrounding vertebral bodies. RESULTS: Multiple lesions were detected in all but two of the 32 patients. On T2-weighted and STIR images, all lesions had homogeneously high signal intensity. On T1-weighted images, the lesions were visible as hypointense areas compared with surrounding bone in all except four patients, in whom the lesions were isointense or hyperintense. All tumor nodules enhanced on turbo-FLASH images obtained in the arterial phase. No additional lesions were seen on STIR or contrast-enhanced images. MR findings resulted in a change in the staging of the disease in one patient and led to prompt treatment in five patients with epidural involvement. CONCLUSION: MR imaging appears to be helpful in detecting spinal involvement in patients with multiple myeloma. The diagnosis of spinal lesions is best achieved by using either fat-suppressed or T2-weighted images. Although myeloma lesions enhanced in all patients, contrast material appears to be of no value for the detection of additional lesions.

Contrast Media↗
PubMed1993

MR appearance of multiple myeloma of the spine before and after treatment.

OBJECTIVE: The aim of this study was to describe the changes in the MR appearance of painful lesions of the spine before and after treatment in 18 patients with multiple myeloma and to correlate these changes with the clinical response to treatment. SUBJECTS AND METHODS: Eighteen patients with multiple myeloma and tumor nodules in the spine had MR imaging of the same site in the spine before and after treatment. Unenhanced T1- and T2-weighted spin-echo images, dynamic ultrafast low-angle shot (turbo-FLASH) images before and after IV bolus injection of paramagnetic contrast material, and contrast-enhanced T1-weighted spin-echo images were obtained. Characteristic signal and contrast enhancement before and after treatment were compared and were correlated with clinical data and the results of immunochemical and pathologic tests. RESULTS: Changes in signal intensity and enhancement of the lesions occurred after treatment in 14 of 18 patients. The characteristics of the lesions after treatment had three patterns: (1) rim enhancement or no enhancement of the lesions, (2) early enhancing lesions associated with other nonenhancing lesions or lesions with rim enhancement, and (3) no change from the enhancement pattern seen before treatment. In 13 of 18 patients, these patterns correlated well with the response to treatment. A discrepancy was observed in five patients. CONCLUSION: The MR appearance of spinal myeloma is different before and after treatment. MR images, particularly contrast-enhanced images, may be helpful in monitoring the response to treatment of focal bone lesions of myeloma.

Combined Modality Therapy↗
PubMed1993

[Role of x-ray computed tomography in the follow-up of the course of Hodgkin's disease].

Fourteen files of patients having had Hodgkin's disease have been analyzed retrospectively to assess the justification of systematic surveillance after complete remission has been achieved. The data of successive CT exams, compared with the findings of clinical and biological studies performed on the same dates, confirm the primordial role of imaging, since computed tomography was predictive for 7 of 18 events (14 relapses and 4 second progressions). The occurrence of subphrenic recurrence in 3 cases for which the initial site was mediastinal leads to discussing the merits of a yearly thoraco-abdomino-pelvic examination during the two years following complete remission.

Adult↗
PubMed1992

Purification of a new galactanase from Penicillium oxalicum catalysing the hydrolysis of beta-(1----5)-galactofuran linkages.

An endo beta-(1----5)-galactofuranase from Penicillium oxalicum has been purified 91-fold. The enzyme is a basic glycoprotein with a pI 7.9 and 20% (w/w) carbohydrate content, galactose being the principal sugar. The apparent Mr of the enzyme estimated by denaturing gel electrophoresis was 77,000. The optimum pH was 5.0, and the enzyme was stable over the pH range 4.0-7.5. This enzyme hydrolyses specifically (1----5)-linked beta-D-galactofuranose residues in homo- and heterogalactans, but did not hydrolyse o-nitrophenyl galactose and beta-(1----5)-galactofuranbiose. Km and Vmax. values were 1.2 mg.ml-1 and 0.55 mumol.h-1 respectively when Eupenicillium crustaceum beta-(1----5)-galactofuran was used as substrate. The enzyme showed high affinity for different separation gels and proteins. The enzyme specificity and its mode of action showed that it could be an useful tool for analysing the fine structure of polysaccharides.

Carbohydrate Conformation↗
PubMed1992

Low grade B cell mucosa associated lymphoid tissue lymphoma of the stomach: clinical and endoscopic features, treatment, and outcome.

A retrospective study of the clinical and endoscopic features of low grade gastric lymphomas of mucosa associated lymphoid tissue (MALT) in 16 patients together with treatment and outcome was undertaken. Immunohistochemical studies of fresh tissue easily distinguished MALT lymphoma from benign reactive lymphoid hyperplasia (pseudolymphoma) and showed that tumour cells had the characteristic phenotype indicative of their origin from MALT. Persistent epigastric pain was the main presenting complaint, and was often associated with acute bleeding, anaemia, or weight loss. Eight patients had a past history of recurrent peptic ulcers or gastritis. The endoscopic appearance suggested malignancy in only half the cases and was compatible with gastritis or a benign peptic ulcer in the remainder. There was extragastric involvement of other mucosal sites in eight patients (mainly the lung, but also the parotid gland and small bowel), but rarely was bone marrow and never the spleen or peripheral lymph nodes affected. Conservative treatment with long term cyclophosphamide was effective in both stage I and stage IV disease, and all the patients are alive after a median follow up of 4.5 years. These findings confirm that low grade gastric MALT lymphomas are usually indolent tumours with non-specific endoscopic aspects and show that dissemination to other mucosal sites was more frequent than previously reported. Monochemotherapy could be an effective alternative treatment to surgery.

Adult↗
PubMed1992

Clinical and biological analysis of peripheral T-cell lymphomas: a single institution study.

Peripheral T-cell lymphoma (PTCL) accounts for 15-20% of non-Hodgkin's lymphoma in the Western World. Clinical, histopathologic, phenotypic and genotypic data were received from 33 cases of PTCL referred to our institution. The median age order was 50 years, 78% were males, and 18% had a history of a preceding disorder of the lymphoid system. 60% had stage 4 at diagnosis and B symptoms were also present in 60%. The most frequent sites of extranodal involvement were bone marrow (54%), liver (45%) and skin (33%). Twenty-eight of 33 cases were histologically classified according to the Working Formulation (most in the diffuse mixed and large-cell subgroups) and the Kiel updated system. Phenotypic and genotypic studies of malignant cells showed a considerable heterogeneity with respect to the expression of either T-cell receptor (TCR) alpha beta and gamma delta and pan-T differentiation molecules. Of the studied cases 63% expressed TCR-alpha beta. All five patients with PTCL of the TCR-gamma delta subtype had a peculiar extra-nodal presentation. The vast majority of cases expressed an abnormal T-cell phenotype with respect to the expression of pan-T antigens, including the lack of expression of the TCR-associated CD3 molecule in 2 cases. Rearrangements of the TCR beta and/or delta-chain genes showed clonality in 21 of the 23 studied cases. Twenty-five patients were treated with a multiagent chemotherapy regimen with curative intent and the remainder received a less intensive palliative regimen. Only 9 patients achieved CR (8 of whom had received an anthracycline-containing regimen) and the 4-year survival rate was 25%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Bone marrow histologic and immunohistochemical findings in peripheral. T-cell lymphoma: A study of 38 cases.

The histologic and immunohistochemical findings in bone marrow (BM) biopsies from 38 patients with peripheral T-cell lymphoma (PTCL) are reported. Routine light microscopy showed that BM involvement was unequivocal in 12 cases and questionable in 14 cases. There was no histologic evidence of lymphoma in the remaining 12 cases. Immunohistochemistry performed on BM frozen sections demonstrated the T-cell origin of the infiltrating lymphoid cells in 24 of the 26 patients with unequivocal or questionable involvement. The malignant nature of these cells was suggested by demonstration of an aberrant T-cell phenotype identical to that observed in the other sites of involvement. In addition, in four of the 12 cases with apparently normal BM at routine light microscopy, immunohistochemistry revealed a minimal but phenotypically abnormal T-cell population, suggesting mild infiltration by lymphoma. These combined histologic and immunohistochemical data documented a high incidence (73%) of BM involvement by PTCL. In addition, a very peculiar sinusal pattern of BM involvement was found in five patients who presented an unusual type of hepatosplenic T-cell lymphoma expressing the gamma delta T-cell receptor. The present study demonstrates the high incidence of BM involvement by PTCL and emphasizes the value of frozen section immunohistochemistry to establish this diagnosis, especially when routine light microscopy findings are questionable.

Adolescent↗
PubMed1991

Recombinative events of the T cell antigen receptor delta gene in peripheral T cell lymphomas.

Recombinative events of the T cell antigen receptor (TCR) delta-chain gene were studied in 37 cases of peripheral T cell lymphoma (PTCL) and related to their clinical presentation and the expression of the alpha beta or gamma delta heterodimers as determined by immunostaining of frozen tissue samples. There were 22 cases of alpha beta, 5 cases of gamma delta, and 10 cases of silent TCR expressing neither the alpha beta nor gamma delta TCR. 5 different probes were used to examine the delta locus. The 22 cases of alpha beta PTCL displayed biallelic and monoallelic deletions; a monoallelic V delta 1 J delta 1 rearrangement was observed in 1 case and a monoallelic germ line configuration in 7 cases. The 5 cases of gamma delta PTCL displayed biallelic rearrangements: the productive rearrangements could be ascribed to V delta 1J delta 1 joining in 3 cases and VJ delta 1 joining in 2 cases according to the combined pattern of DNA hybridization with the appropriate probes and of cell reactivity with the TCR delta-1, delta TCS-1, and anti-V delta 2 monoclonal antibodies. In the VJ delta 1 joining, the rearranged V segments were located between V delta 1 and V delta 2. Interestingly, in the third group of 10 cases of silent PTCL, 5 cases were found to have a TCR gene configuration identical to that in the TCR alpha beta PTCL, as demonstrated by biallelic delta gene deletion. These 5 cases were CD3 positive. The 5 remaining cases showed a monoallelic delta gene rearrangement with a monoallelic germ line configuration in 4 and a monoallelic deletion in 1. Four of these cases were CD3 negative, which was consistent with an immature genotype the TCR commitent of which could not be ascertained. Finally, TCR gamma delta PTCL consisted of a distinct clinical morphological and molecular entity whereas TCR alpha beta and silent PTCL had a similar presentation.

Alleles↗
PubMed1991

Cutaneous lymphomas other than mycosis fungoides: follow-up study of 52 patients.

Cutaneous lymphomas other than mycosis fungoides (MF) represent a rare and heterogeneous group of lymphomas. Their clinical behavior remains largely unknown. In this study, the clinical and immunohistologic characteristics and follow-up data of 52 well-documented cases of cutaneous lymphomas other than MF, presenting with initial cutaneous lesions, were reviewed. Twenty-seven patients presented with skin disease alone (stage IE), and 25 patients had concurrent cutaneous and extracutaneous disease (stage IV). The tumors were grouped into high-grade lymphomas (HGLs; 21%), intermediate-grade lymphomas (IGLs; 58%), and low-grade lymphomas (LGLs; 21%). A B-cell phenotype was most often expressed by cutaneous lymphomas (73%), particularly by stage IE lymphomas (85%). Among 13 cases of T-cell lymphomas, loss of one of the pan-T-cell antigens was detected in all cases but one. The clinical course of cutaneous lymphoma was closely dependent on stage and histologic subtype but not on T-cell or B-cell phenotype. Of 20 patients with stage IV HGL or IGL, 13 were treated by polychemotherapy with curative potential. Their median survival was 37 months. Fourteen patients with stage IE HGL or IGL were treated by radiotherapy alone. Nine patients (69%) relapsed within 2 years posttreatment. Seven of them relapsed in the skin outside the initial site involved, suggesting that radiotherapy alone is not an adequate treatment for these patients. Preliminary results concerning seven other patients with stage IE IGL or HGL treated by an initial third-generation polychemotherapy regimen are presented.

Adolescent↗
PubMed1990

Polymerase chain reaction (PCR) amplification demonstrates the absence of human T-cell lymphotrophic virus (HTLV)-I specific pol sequences in peripheral T-cell lymphomas.

HTLV-I seronegative patients in nonendemic areas have been described with T-cell proliferations the DNA of which contains specific HTLV-I viral sequences. We have looked for the presence of HTLV-I DNA sequences in 27 HTLV-I seronegative patients with peripheral T-cell lymphomas, distinct from adult T-cell leukemia (ATL), and four HTLV-I seropositive patients, three with an ATL and one with a tropical spastic paraparesis. Using HTLV-I pol specific primers, the genomic DNA from peripheral blood mononuclear cells and lymph nodes massively infiltrated by tumor cells was analyzed by the enzymatic gene amplification procedure. In contrast to the peripheral blood lymphocytes from the four HTLV-I seropositive patients, the peripheral T-cell lymphoma samples did not harbor HTLV-I pol sequences. The data show that the detection of HTLV-I nucleotide sequences by the polymerase chain reaction correlates with serologic analysis in this series.

Base Sequence↗
PubMed1990

Nucleases in the autolysis of filamentous fungi.

RNase and DNase activities were studied in seven fungi of the subdivisions Ascomycotina, Zygomycotina and Basidiomycotina during their autolysis, and extracellular and intracellular RNase and DNase were found. RNase specific activity reached higher levels than DNase specific activity in the culture liquid and mycelial extract, except in Aspergillus nidulans. Generally maximal RNase specific activities were observed at the onset of autolysis in the culture liquid. In the mycelial extract an increase in this activity with the incubation time was observed, except in A. nidulans and Coriolus versicolor. The highest values of DNase specific activities were found at the third day of autolysis in A. nidulans culture liquid and at the thirtieth day of autolysis in Schizophyllum commune mycelial extract. A possible relationship between the culture liquid pH during the autolysis of the studied fungi and the levels of DNase specific activity was observed.

Ascomycota↗
PubMed1990

CD3-T cell receptor modulation is selectively induced in CD8 but not CD4 lymphocytes cultured in agar.

The CD3-T cell receptor (TcR) complex is central to the immune response. Upon binding by specific ligands, internalized CD3-TcR molecules increase, and either T cell response or unresponsiveness may ensue depending on the triggering conditions. Using semi-solid agar culture, we have shown previously that quiescent CD4 but not CD8 lymphocytes generate clonal colonies under phytohaemagglutinin stimulation. Here we have demonstrated that the agar induces selective CD3-TcR modulation in the CD8 and not in the CD4 subset. CD8 lymphocytes preactivated in liquid culture and recultured in agar with exogenous recombinant interleukin-2 generate colonies with a modulated CD3-TcR surface expression. The peptides composing the CD3-TcR complex are synthesized in CD8 colonies as well as in CD4; however, the CD3 gamma chain is phosphorylated at a higher level in CD8 colonies. A component of the agar polymer, absent in agarose, appears to be the ligand that induces differential CD3-TcR modulation in the CD8 subset. In contrast to agar culture, CD8 colonies can be derived from quiescent CD8 lymphocytes in agarose. These CD8 colonies express unmodulated CD-TcR. CD3-TcR modulation with anti-CD3 monoclonal antibody prior to culturing in agarose inhibits the colony formation. We conclude that given triggering conditions can result in both CD3-TcR modulation and inhibition of the proliferative response selectively in the CD8 lymphocyte subset and not in the CD4.

Agar↗
PubMed1990

Effect of beta-glucanases on Penicillium oxalicum cell wall fractions.

The polysaccharidic effect of a purified 1,3-beta-glucanase, a purified beta-glucosidase, and of partially purified endo-1,3-beta-glucanase from autolysed Penicillium oxalicum cultures on cell wall isolate fractions from the same fungus were studied. Fractionation of 5-day-old cell wall gave rise to a series of fractions that were identified using infrared spectrophotometry. The fractions used were: F1, an alpha-glucan; F3, a beta-glucan; F4, a chitin-glucan; and F4b, a beta-glucan. The fractions were incubated with each of the enzymes and with a mixture of equal parts of the three enzymes and the products of the enzymatic hydrolysis were analyzed after 96 h incubation. The enzymes were found to degrade fraction F4b (beta-glucan); the greatest degree of hydrolysis was reached when the three enzymes were used together, suggesting the need for synergic action by these enzymes in the cell wall degradation process.

Cell Wall↗
PubMed1990

Cephalosporin C acylase in the autolysis of filamentous fungi.

Cephalosporin C acylase activity was studied using fluorescamine determination of free--NH2 groups produced in the deacylation of cephalosporin C by the enzyme. Fourteen fungi from different genera were studied and low extracellular cephalosporin C acylase activity was found in the genera Aspergillus, Fusarium and Penicillium. Forty one fungi of these genera were checked but not all presented acylase activity. The enzyme was generally found to be an extracellular enzyme and during the process of autolysis its activity increased with incubation time and with increasing pH of the medium. In no case was beta-lactamase activity detected. Penicillium rugulosum and Penicillium griseofulvum were identified as good cephalosporin C acylase producers. Deacetyl esterase activity was also detected in these fungi.

Amidohydrolases↗