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Biomedical subjects

A Domingo

Publications and source records attributed to A Domingo.

At least 19 recordsLinked to original sources

[Clinical course of severe acquired aplastic anemia to myelodysplastic syndrome and acute leukosis].

Survival of patients with severe acquired aplastic anemia has improved dramatically during the past decade mainly due to the use of new treatments. The long-term follow-up of these patients has allowed to observe an increased incidence of late malignant hematological complications such as myelodysplastic syndromes and leukemia, which raises the question whether they are just different forms of presentation of the same disease. We report two cases of severe acquired aplastic anemia with long-time survival, one of them developed a myelodysplastic syndrome and the other one a myelodysplastic syndrome followed by an acute leukemia. We discuss the factors associated with a high risk to develop myelodysplastic syndrome and acute leukemia, and its repercussions in therapy.

Adult

Granular lymphocyte proliferative disorders: a multicenter study of 20 cases.

A series of 20 patients with granular lymphocyte proliferative disorders (GLPD) is reported. The criterion of inclusion was presence of persistent (> or = 6 months) granular lymphocytosis in the absence of any causative illness. Diagnoses made upon analytical control in half the patients of splenomegaly (25%) and hepatomegaly (25%) were infrequent. Clinical course was nonprogressive in 17/20 patients, but two developed high-grade NHL several years later and one showed progressive disease. Actuarial probability of survival at 5 years was 85%. Granular lymphocyte morphology was relatively homogeneous, and peripheral blood counts were preserved in the most patients. Bone marrow lymphocytic infiltration was low, as assessed by bone marrow aspiration and/or biopsy. Eosinophilia was an outstanding feature in eight cases. Ultrastructurally, all cases showed parallel tubular arrays; cytoplasmic granules and numerous short microvilli were noticed. The lymphoid phenotype was heterogeneous, the most common being CD2+CD3+CD4-CD8+, but six patients (30%) were CD4+ with variable expression of natural killer-associated antigens. Chromosomal analysis was abnormal in 4/10 patients [trisomy 19, t(5;6); inv(14) and inv(10)]. The study of beta-chain of the T-cell receptor revealed clonal rearrangements in 14 (78%), restricted to CD3+ patients (92%). In vitro culture of myeloid precursors showed decreased CFU-GM in 5/6 patients. Virological studies for HTLV-I and II were negative. In conclusion, the presence of a clonal proliferation was not correlated with the clinical course or an associated disease.

Aged

Phosphatidylcholines as mediators of adaptive cytoprotection of the rat duodenum.

BACKGROUND/AIMS: Surfactant phospholipids impede diffusion of acid through the gastric mucus, but their relevance in the defense of the duodenum against luminal acid is not known. METHODS: Duodenal resistance to acid was tested in anesthetized rats by instillation of HCl using a tube implanted in the proximal duodenum. The effects of a detergent (Brij 35; Sigma, St. Louis, MO) and a lipid mixture flushed through the luminal surface on duodenal resistance to acid were studied. The lipid content in the mucus and the effects of acid, prostaglandins, and indomethacin on the lipid layer were also analyzed. RESULTS: Instillation of 100 mumol HCl or 5 micrograms/kg 16,16-dimethyl prostaglandin E2 increased resistance to acid, preventing duodenal lesions induced by 500 mumol HCl. However, 100 mumol HCl or 16,16-dimethyl prostaglandin E2 did not prevent lesions induced by 500 mumol HCl in rats undergoing perfusions with 5% Brij 35. Indomethacin suppressed acid-induced protection. A mixture of tripalmitin and dipalmitoyl-phosphatidylcholine protected against 500 mumol HCl, and the effect was also observed in rats receiving indomethacin. Finally, 100 mumol HCl increased the phosphatidylcholine content in the duodenal mucus but not in rats receiving 5% Brij 35 or indomethacin. CONCLUSIONS: Surface-active phospholipids are critical for adaptive cytoprotection to acid in the rat duodenum.

16,16-Dimethylprostaglandin E2

Localized fibrous tumor of the pleura: immunohistochemical and flow-cytometric DNA study.

This report describes three cases of localized fibrous tumor of the pleura (LFTP) with clinical and pathological differences. Case 1 presented with symptoms; the tumor size was 6.5 cm and it was attached to the lung and chest wall; histologically it was composed of spindle cells with pleomorphism, mitoses, hemorrhage and necrosis. Cases 2 and 3 were casual findings and consisted of well-circumscribed tumors of 3 and 8.5 cm, respectively; histologically both showed hypocellularity. All cases exhibited positive stains for vimentin and negative for keratin. These results, added to histological features, suggested a mesenchymal origin. Flow cytometry quantitation of DNA disclosed a diploid pattern in all three cases with a small "near diploid" cell population additionally in Case 1; the S-phase fraction was low in all cases. These findings, that could be considered favourable prognostic signs, and the complete tumoral resection performed in the three tumors, could explain the absence of recurrences after 32, 27 and 19 months, respectively.

Aged

Vimentin's tail interacts with actin-containing structures in vivo.

The tail domain of the intermediate filament (IF) protein vimentin is unnecessary for IF assembly in vitro. To study the role of vimentin's tail in vivo, we constructed a plasmid that directs the synthesis of a 'myc-tagged' version of the Xenopus vimentin-1 tail domain in bacteria. This polypeptide, mycVimTail, was purified to near homogeneity and injected into cultured Xenopus A6 cells. In these cells the tail polypeptide co-localized with actin even in the presence of cytochalasin. Two myc-tagged control polypeptides argue for the specificity of this interaction. First, a similarly myc-tagged lamin tail domain localizes to the nucleus, indicating that the presence of the myc tag did not itself confer the ability to co-localize with actin (Hennekes and Nigg (1994) J. Cell Sci. 107, 1019-1029). Second, a myc-tagged polypeptide with a molecular mass and net charge at physiological pH (i.e. -4) similar to that of the mycVimTail polypeptide, failed to show any tendency to associate with actin-containing structures, indicating that the interaction between mycVimTail and actin-containing structures was not due to a simple ionic association. Franke (1987; Cell Biol. Int. Rep. 11, 831) noted a similarity in the primary sequence between the tail of the type I keratin DG81A and vimentin. To test whether the DG81A tail interacted with actin-containing structures, we constructed and purified myc-tagged DG81A tail polypeptides. Unexpectedly, these keratin tail polypeptides were largely insoluble under physiological conditions and formed aggregates at the site of injection. While this insolubility made it difficult to determine if they associated with actin-containing structures, it does provide direct evidence that the tails of vimentin and DG81A differ dramatically in their physical properties. Our data suggest that vimentin's tail domain has a highly extended structure, binds to actin-containing structures and may mediate the interaction between vimentin filaments and microfilaments involved in the control of vimentin filament organization (Hollenbeck et al. (1989) J. Cell Sci. 92, 621; Tint et al. (1991) J. Cell Sci. 98, 375).

Actins

Prognostic factors in patients who received autologous bone marrow transplantation for non-Hodgkin's lymphoma. Report of 104 patients from the Spanish Cooperative Group GEL/TAMO.

One hundred and four patients with low grade (9 patients), intermediate grade (31 patients) and high grade (64 patients) non-Hodgkin's lymphoma received an autologous bone marrow transplantation (BMT). Disease status at transplant was first complete remission (CR) in 46 patients, second CR in 14 patients, third CR in 7 patients, chemosensitive disease in 16 patients and chemoresistant disease in 21 patients. Estimated 5 year disease-free survival (DFS) for all 104 patients was 49% (95% confidence interval (CI), 36-63%) with a median follow-up of 24 months. Five year relapse rate for 80 evaluable patients was 26% (95% CI, 14-44%). The 8 year DFS and relapse for the 46 patients transplanted in first CR were 75% (95% CI, 63-82%) and 15% (95% CI, 7-33%), respectively, with a median follow-up of 27 months (range 13-104 months) and a median time to relapse of 5 months (range 4-20 months). In the univariate analysis, variables correlated with DFS were performance status at autologous BMT, disease status at autologous BMT, LDH level at autologous BMT, failure to achieve CR at diagnosis, front-line chemotherapy (1 vs 2 or more regimens) and Working Formulation. Variables correlated with relapse were disease status at autologous BMT, preparative regimen and Coiffer's index at diagnosis. Multivariate analysis showed that performance status was the only independent predictor of DFS and that disease status at autologous BMT was the best relapse predicting variable. In patients transplanted in first CR, the variables correlated with DFS were stage at diagnosis and performance status at autologous BMT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Hematological recovery after autologous bone marrow transplantation in acute leukemia: predictive factors.

The kinetics of hematological recovery after autologous marrow transplantation have been studied in 70 patients with acute leukemia (38 acute nonlymphoblastic leukemia [ANNL] and 32 acute lymphoblastic leukemia [ALL]). The incidence of graft failure in this group was 3.2%, and a persistent severe thrombocytopenia was observed in 24% of the cases. Variables influencing engraftment have been studied using univariate and multivariate statistical analysis. Analysis of the entire group showed a correlation between graft colony-forming unit granulocyte-macrophage (CFU-GM) content and granulocyte recovery (p < 0.001). Marrow purging was associated with a delayed engraftment (p < 0.001). In ANLL patients, we found that high cummulated AraC doses before marrow cryopreservation correlated with poor granulocyte recovery after marrow infusion (p < 0.002). Platelet recovery was essentially affected by age, with shorter thrombocytopenia periods in younger patients (p < 0.001). Finally, excluding autotransplants with purged marrows, ALL patients showed better platelet recoveries than ANLL patients (p < 0.005). These findings will be useful to evaluate the risk of delayed engraftment after autologous bone marrow transplantation (ABMT) in patients with acute leukemia.

Acute Disease

Host cell factors controlling vimentin organization in the Xenopus oocyte.

To study vimentin filament organization in vivo we injected Xenopus oocytes, which have no significant vimentin system of their own, with in vitro-synthesized RNAs encoding Xenopus vimentins. Exogenous vimentins were localized primarily to the cytoplasmic surface of the nucleus and to the subplasma membrane "cortex." In the cortex of the animal hemisphere, wild-type vimentin forms punctate structures and short filaments. In contrast, long anastomosing vimentin filaments are formed in the vegetal hemisphere cortex. This asymmetry in the organization of exogenous vimentin is similar to that of the endogenous keratin system (Klymkowsky, M. W., L. A. Maynell, and A. G. Polson. 1987. Development (Camb.). 100:543-557), which suggests that the same cellular factors are responsible for both. Before germinal vesicle breakdown, in the initial stage of oocyte maturation, large vimentin and keratin filament bundles appear in the animal hemisphere. As maturation proceeds, keratin filaments fragment into soluble oligomers (Klymkowsky, M. W., L. A. Maynell, and C. Nislow. 1991. J. Cell Biol. 114:787-797), while vimentin filaments remain intact and vimentin is hyperphosphorylated. To examine the role of MPF kinase in the M-phase reorganization of vimentin we deleted the conserved proline of vimentin's single MPF-kinase site; this mutation had no apparent effect on the prophase or M-phase behavior of vimentin. In contrast, deletion of amino acids 19-68 or 18-61 of the NH2-terminal "head" domain produced proteins that formed extended filaments in the animal hemisphere of the prophase oocyte. We suggest that the animal hemisphere cortex of the prophase oocyte contains a factor that actively suppresses the formation of extended vimentin filaments through a direct interaction with vimentin's head domain. During maturation this "suppressor of extended filaments" appears to be inactivated, leading to the formation of an extended vimentin filament system.

Amino Acid Sequence

Hairy cell leukemia and autoimmune hemolytic anemia.

A case of hairy cell leukemia (HCL) presenting as autoimmune hemolytic anemia (AHA) is described. A 40-year-old woman presented with severe hemolytic anemia. The morphological and immunological studies of bone marrow and spleen revealed a hairy cell leukemia. Although autoimmune diseases are a well known complication of HCL this is the first description of AHA as a complication of HCL.

Adult

Identification and characterization of Drosophila melanogaster paramyosin.

Paramyosin, a major structural component of thick filaments in invertebrates has been isolated, purified and characterized from whole adult Drosophila melanogaster extracts and a specific polyclonal antibody against it has been prepared. Paramyosin has been identified on the basis of several criteria, including molecular weight, alpha-helicity, species distribution, capability of fiber formation in vitro and sequence. We have used the immunopurified polyclonal antibody to isolate eight clones from a lambda gt11 expression library of Drosophila 1 to 22 h embryo cDNA. The largest clone (pJV9) has been sequenced and encodes the coiled-coil region of D. melanogaster paramyosin that is 47% identical to Caenorhabditis elegans paramyosin. Indirect immunofluorescence in semi-thin sections of adult flies show fluorescence mainly in tubular muscle. Freshly prepared tubular myofibrils decorated with the immunoabsorbed antibody show the A region in the sarcomere as the specific localization of paramyosin. The amount of paramyosin in tubular synchronous muscles of insects appears to be five times higher than in fibrillar insect muscles. There are at least three paramyosin isoforms as shown by isoelectrofocusing separation. The more acidic and less abundant form is phosphorylated as shown by 32P in vivo labeling experiments in adult flies. The developmental pattern of expression of Drosophila paramyosin is presented. This mesoderm-specific protein, immunologically undetectable during gastrulation and early phases of germ band formation, progressively increases during organogenesis to the adult stage. Interestingly, it is also expressed as a major maternal product in the insoluble cytoskeletal fraction of the mature oocyte.

Amino Acid Sequence

Epidemiological surveillance of opioid-related episodes in an emergency room of Barcelona, Spain (1979-1989)

In the early 80's opioid addiction was a low prevalence problem in Spain, grew enormously during that decade and became the most important risk factor for AIDS in recent years. The limitations of assessing the prevalence of illegal drug use by means of standard epidemiological methods lead, worldwide, to the use of indirect indicators. A Register of Toxicological Emergencies, developed for research purposes and containing data from 1979 to 1989 at the Hospital del Mar (Barcelona) is described. Results for opioid-related emergencies are presented, showing an epidemic increase in the number of such emergencies after 1981. The total number of opioid-related emergencies was 18,042 with a mean of 2.23 opioid-related emergency admissions per client throughout the whole period, implying that some 8000 persons were seen. In episodes from non-arrestees, mean age increased slightly over time, the male/female ratio being 2.5; withdrawal was the more frequent reason for attendance (53%), overdose accounting for 9% of admissions, and other medical conditions for 33%. Non-arrested women were more likely to attend for other medical conditions and overdoses than men. The importance of this kind of register as well as its limitations for assessing the trend of opioid use prevalence is discussed.

Adolescent

[Pericardial tamponade as a complication of T-cell cutaneous lymphoma].

Mycosis fungoides is a T cell lymphoma characterized by the initial skin involvement. Organ infiltration generally occurs many years after the cutaneous presentation. The organ disease is accompanied of peripheral blood involvement (more than 20% lymphocytes have atypical convolute nucleus and there are palpable adenopathies. Pericardic involvement is a rare complication as the initial manifestation of the visceral disease, in patients with mycosis fungoides of long evolution. We present a patient suffering mycosis fungoide who presented a pericardic tamponade. The visceral disease in our patient was not accompanied by blood anomalies or palpable adenopathies.

Cardiac Tamponade

Exponential gradient maker using a disposable syringe.

With a simple modification, any disposable syringe can become a reliable and easy to use exponential gradient maker. The modification consists of two notches, made with a razor blade, in the borders of the rubber sealing tip of the plunger. A clamp in the tube connected to the syringe allows control over solution flow. With the clamp prohibiting drainage, the body of the syringe is filled with the desired volume of starting solution I. A magnetic stir bar, small enough to spin inside the syringe is included. The notched plunger is introduced until no air space remains. This forms the fixed volume, closed mixing chamber, while the rest of the volume of the syringe forms the open chamber. The two chambers are connected through the notches in the plunger. The ending solution II is poured after the introduction of the plunger. Opening the clamp allows solution I in the closed chamber to flow out, and the solution II in the open chamber flows through the notches and mixes with solution I. This exponential gradient maker can be reused many times, but the low cost of the components makes it potentially disposable. This feature is especially useful when using toxic chemicals, or when pouring polyacrylamide gradient gels, since the apparatus may be disposed of after contamination or eventual polymerization.

Chemistry Techniques, Analytical

Determination of C3 nephritic factor activity by a microassay based on the peroxidase-like activity of the heme group.

We report a modification of a method for measuring the C3 nephritic factor, using the peroxidase activity of the heme group. This modification increases the sensitivity of the method, approximately seven-fold when NEF activities are measured in U/mL. It is less time-consuming and it allows the simultaneous testing of a larger number of samples, simplifying the screening of sera and ensuring an easy and simple test for the detection of NEF in purification processes as well as in in vitro production. The method could also be useful in other hemolytic assays.

Biological Assay

Simultaneous occurrence of cutaneous T cell lymphoma and low-grade B cell lymphoproliferative diseases. A report of two cases.

Two previously unreported patients with cutaneous T cell lymphoma associated with systemic low-grade B cell proliferations are presented. The first patient had Waldenström's macroglobulinemia and the second had simultaneous chronic lymphocytic leukemia. The use of immunosuppressive drugs or a genetic predisposition may have contributed to the second malignancy. However, the possibility that malignant helper/inducer T lymphocytes were a factor in the promotion of the proliferation of B cells cannot be excluded.

Aged