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Biomedical subjects

J M Rodriguez

Publications and source records attributed to J M Rodriguez.

At least 55 records · Page 3Linked to original sources
PubMed1997

Measurement and application of uranium isotopes for human and environmental monitoring.

An improved method is described utilizing extraction chromatography, anion exchange, and alpha spectroscopy for measurement of uranium isotopes in human and environmental surveillance studies. These methods provide a sensitivity of approximately 0.7 mBq per isotope per sample and are generally accurate within the precision of the measurements. The extraction chromatography methods greatly simplify separation of uranium from iron in silicate matrices and provide increased sample throughput and data quality for water, soil, and air filter samples. For bioassay samples, the coprecipitation/anion exchange/alpha spectrometric methods provide rapid throughput and sufficient sensitivity to meet new analytical performance standards in human monitoring studies. In addition, the 234U:238U data can be used as a fingerprint of natural vs. anthropogenic sources of uranium. For 1995 data from our laboratory, a large percentage (79-94% by matrix) of samples appear to be of natural 234U:238U isotopic composition. For all matrices, samples with higher uranium concentration generally have more depleted isotopic composition (smaller 234U:238U). A small percentage of soil (11%), air filter (3%), urine (3%), and water (3%) samples have depleted isotopic signatures at the 95% confidence interval, indicating anthropogenic contributions of uranium to these samples.

Air Pollutants, Radioactive↗
PubMed1997

Papillary thyroid microcarcinoma: clinical study and prognosis.

OBJECTIVE: To study the anatomical and prognostic characteristics of papillary thyroid microcarcinomas (10 mm or less in size). DESIGN: Retrospective review. SETTING: Community hospital, Spain. SUBJECTS: 36 patients with papillary microcarcinomas diagnosed over a period of 20 years from a total of 158 papillary carcinomas with complete follow-up. MAIN OUTCOME MEASURES: Symptoms, treatment, histopathological confirmation and follow-up compared with those of papillary carcinomas more than 10 mm in size. RESULTS: Six of the patients with microcarcinomas presented with adenopathy, the remaining 30 being admitted for treatment of associated thyroid diseases. In 15 cases the tumour was 5 mm or less in size. Thirty were well-differentiated, 2 were follicular, and 2 showed signs of diffuse sclerosis. Three had recurred after total thyroidectomy, but no patient died. When the results were compared with those of the patients with larger tumours, we found differences in histological type (p = 0.001), the incidence of adenopathy (p = 0.03), TNM stage (p = 0.001) and mortality (p = 0.04). CONCLUSIONS: There are clinical, histopathological, and prognostic differences between microcarcinomas (which do well) and larger papillary tumours.

Adolescent↗
PubMed1996

Cytogenetic analysis in human bone marrow transplantation.

Bone marrow transplantation (BMT) is a therapeutic process used to treat a variety of hematologic diseases. After BMT, the documentation of engrafting with the use of genetic markers is obligatory. C-band polymorphism is an excellent genetic marker because it occurs with high frequency in all populations studied and shows a high stability in vitro and in vivo. We studied a total of 36 patients: 15 with myeloid leukemia and 21 with severe aplastic anemia (SAA), submitted to BMT. The majority of the patients with chronic granulocyte leukemia (CGL; 10/15, 67%) and with SAA (17/21, 81%) showed a frequency of host cells around 15% (CGL) and 8% (SAA) in the first period analyzed (day +30 post-BMT); with a decrease in the others (+90, +180 to CGL and SAA and +365 only to CGL). In our study, the persistence of host cells in these proportions did not imply an unfavorable prognosis. On the contrary, some patients with myeloid leukemia (5/15 33%) and SAA (4/21, 19%) showed high proportions of host cells in one or more periods analyzed. If compared to the first group, these patients had, in general, a poor clinical evolution, with rejections, relapses, and deaths in greater numbers. These results show the important contribution of cytogenetic analysis in the follow-up of patients submitted to BMT.

Adolescent↗
PubMed1996

Encapsulated papillary neoplasm of the thyroid: retrospective clinicopathological study with long term follow up.

OBJECTIVE: To study the clinical course of patients with the encapsulated variant of papillary thyroid carcinoma, in which there is a well-defined fibrous wall completely separating the tumour cells from the adjacent tissue. DESIGN: Retrospective review. SETTING: University hospital, Spain. SUBJECTS: Of a total of 163 patients whose papillary thyroid carcinomas were treated surgically between 1975 and 1985, there were 25 encapsulated tumours. MAIN OUTCOME MEASURES: Clinicopathological features and survival rate compared with those of non-encapsulated papillary thyroid carcinomas. RESULTS: Mean follow up was 9 years (range 7-17), and 42 were excluded because follow up was incomplete. Encapsulated tumours differed from the earlier age of other types in that they presented earlier (mean age 36 years compared with 45), they were significantly less likely to have symptoms of compression (1/25 compared with 24/96, p = 0.024), or nodal metastases (3/25 compared with 43/96, p = 0.002), or to recur (0/25 compared with 33/96, p = 0.002). No patients died in the encapsulated group compared with 11/96 in the other group. CONCLUSIONS: Encapsulated papillary carcinomas have an excellent prognosis, and can be cured by operation.

Adolescent↗
PubMed1995

Combined chemotherapy and radiotherapy in diffuse large cell immunoblastic lymphoma: a phase II study of CHOP/bleomycin/methotrexate alternating with ifosfamide/methotrexate/etoposide.

The clinical outcome of 23 patients with high grade diffuse large cell immunoblastic lymphoma (Working Formulation, category H) treated by an intensive shortened schedule regimen of chemotherapy is described. Alternating cycles of cyclophosphamide, doxorubicin, vincristine, bleomycin and prednisolone, and ifosfamide, etoposide and methotrexate were given over an 18-week (range 16.0-20.8) period. External beam radiotherapy was administered as consolidation therapy to sites of original bulky disease in 17 patients. Treatment was well tolerated, though there were two toxic deaths. A 90% response rate was obtained. Sixteen of 18 patients followed for a minimum of 36 months are alive and in complete remission, representing a disease free survival of 69.5%; two further patients are alive following autologous bone marrow transplant. The 3-year disease free survival was 73% (+/- 9%) and the overall 3-year survival 78% (+/- 9%).

Adolescent↗
PubMed1995

Isolation and characterization of pediocin L50, a new bacteriocin from Pediococcus acidilactici with a broad inhibitory spectrum.

Lactic acid bacteria were isolated from Spanish dry-fermented sausages and screened for bacteriocin production. About 10% of the isolates produced antimicrobial substances when grown on solid media, but only 2% produced detectable activity in liquid media. Strain L50, identified as Pediococcus acidilactici, showed the strongest inhibitory activity and was active against members of all of the gram-positive genera tested. The strain produced a heat-stable bacteriocin when grown at 8 to 32 degrees C but not at 45 degrees C. The bacteriocin was purified to homogeneity. Its mass was determined to be 5,250.11 +/- 0.30 by electrospray mass spectrometry. The N terminus of the bacteriocin was blocked for sequencing by Edman degradation, but a partial sequence of 42 amino acids was obtained after cleavage of the peptide by cyanogen bromide. The sequence showed no similarity to those of other bacteriocins. Pediocin L50 appears to contain modified amino acids but not lanthionine or methyl-lanthionine.

Amino Acid Sequence↗
PubMed1995

Primary hyperparathyroidism in patients who have received radiation therapy and in patients who have not received radiation therapy.

BACKGROUND: Primary hyperparathyroidism (HPT) occurs more frequently in persons who have been exposed to low-dose therapeutic radiation. Little information is available concerning whether or not the clinical, metabolic, and pathologic manifestations, as well as outcome, differ in these patients when compared with patients with sporadic HPT. STUDY DESIGN: Records from 438 unselected patients with primary HPT, who were treated from 1982 to 1993 were retrospectively analyzed. All patients prospectively received a standard questionnaire preoperatively and postoperatively concerning clinical manifestations and a history of radiation exposure. Forty-nine patients had a history of radiation exposure (rHPT), whereas 389 did not have sporadic HPT (sHPT). RESULTS: There was no difference in gender (36 women and 13 men versus 289 women and 100 men) or age (mean of 52 +/- 12 versus 57 +/- 16 years) in patients with rHPT or sHPT. Fatigue, neuropsychiatric disorders, memory loss, nocturia, and polyurea were more common in patients with sHPT (p < 0.05), whereas pain in joints was more common in patients with rHPT (63 versus 52 percent; p < 0.001). Serum calcium levels were similar (11.1 +/- 0.8 versus 11.2 +/- 0.8 mg per dL), but serum parathyroid hormone levels were higher in rHPT (448 +/- 14 percent of upper limit of normal versus 371 +/- 12 percent upper limit of normal). The parathyroid pathology was similar in the two groups (single adenoma 74 versus 72 percent, hyperplasia 14 versus 16 percent, and double adenoma 12 versus 12 percent in rHPT versus sHPT, respectively). Thyroid pathology was more common in the rHPT group (multinodular goiter 27 versus 7 percent and papillary thyroid carcinoma 14 versus 0.3 percent). Seven (1.8 percent) of patients not receiving radiation therapy treated by us had persistent HPT, but no patients receiving or not receiving radiation therapy had recurrent HPT during the follow-up period (six years). CONCLUSIONS: Patients who have HPT after radiation treatment have more thyroid neoplasms but are otherwise quite similar to other patients with primary hyperparathyroidism.

Adolescent↗
PubMed1994

Elevated CA125 levels in association with Ki-1 anaplastic lymphoma.

CA125 is a tumour marker usually associated with epithelial ovarian malignancy. A case history is reported of a patient with Ki-1 anaplastic large cell lymphoma associated with grossly elevated CA125 levels which reflected the clinical course of the disease. Expression of this tumour marker by lymphoma has not been previously described.

Aged↗
PubMed1994

T-cell receptor gene rearrangements in lymphoid and non-lymphoid leukaemias.

Rearrangements of delta-, tau-, and beta- T-cell receptor (TcR) chain genes were analysed in 64 haematologic malignancies comprising T- and B-lineage acute lymphoblastic leukaemias (ALL), B-chronic lymphocytic leukaemias (CLL), acute myeloid leukaemias (AML) and acute undifferentiated leukaemias AUL). The TcR genes were rearranged in 5/6 T-ALL. In non-T-leukaemias the frequency of TcR gene rearrangements was higher in B-lineage ALL (8/11), although they were all detected in B-CLL (5/29), AML (1/16) and AUL (2/4). Immunoglobulin (Ig) gene rearrangements were observed in 1/6 T-ALL and 2/14 AML. The analysis of these gene configurations has a diagnostic application since it allows the definition of the clonality of malignant proliferation and although they are not lineage specific such configurations represent a further parameter to evaluate, together with the immunophenotype and morphology, in the assignment or exclusion of the differentiation lineage of the haematologic malignancies.

Gene Rearrangement, T-Lymphocyte↗
PubMed1994

Characterization and molecular basis of heterogeneity of the African swine fever virus envelope protein p54.

It has been reported that the propagation of African swine fever virus (ASFV) in cell culture generates viral subpopulations differing in protein p54 (C. Alcaraz, A. Brun, F. Ruiz-Gonzalvo, and J. M. Escribano, Virus Res. 23:173-182, 1992). A recombinant bacteriophage expressing a 328-bp fragment of the p54 gene was selected in a lambda phage expression library of ASFV genomic fragments by immunoscreening with antibodies against p54 protein. The sequence of this recombinant phage allowed the location of the p54 gene in the EcoRI E fragment of the ASFV genome. Nucleotide sequence obtained from this fragment revealed an open reading frame encoding a protein of 183 amino acids with a calculated molecular weight of 19,861. This protein contains a transmembrane domain and a Gly-Gly-X motif, a recognition sequence for protein processing of several ASFV structural proteins. In addition, two direct tandem repetitions were also found within this open reading frame. Further characterization of the transcription and gene product revealed that the p54 gene is translated from a late mRNA and the protein is incorporated to the external membrane of the virus particle. A comparison of the nucleotide sequence of the p54 gene carried by two virulent ASFV strains (E70 and E75) with that obtained from virus Ba71V showed 100% similarity. However, when p54 genes from viral clones generated by cell culture passage and coding for p54 proteins with different electrophoretic mobility were sequenced, they showed changes in the number of copies of a 12-nucleotide sequence repeat. These changes produce alterations in the number of copies of the amino acid sequence Pro-Ala-Ala-Ala present in p54, resulting in stepwise modifications in the molecular weight of the protein. These duplications and deletions of a tandem repeat sequence array within a protein coding region constitute a novel mechanism of genetic diversification in ASFV.

African Swine Fever Virus↗
PubMed1994

Multigene families in African swine fever virus: family 505.

Sequencing of restriction fragment EcoRI A-SalI C of African swine fever virus has revealed the existence of a multigene family, designated family 505 because of the average number of amino acids in the proteins, composed of seven homologous and tandemly arranged genes. All the genes of family 505 are expressed during infection. Primer extension analysis showed that transcription is initiated a short distance (3 to 62 nucleotides) from the start codon of the corresponding open reading frame. The proteins of family 505 showed similarity to those of family 360 from African swine fever virus. In particular, a striking conservation of three regions at the amino terminus of the polypeptides was observed.

African Swine Fever Virus↗
PubMed1994

Effect of pentoxifylline on the inhibition of surfactant synthesis induced by TNF-alpha in human type II pneumocytes.

Tumor necrosis factor alpha (TNF-alpha) seems to play an important role in the pathogenesis of the adult respiratory distress syndrome (ARDS). This study was designed to determine the effect of TNF-alpha and pentoxifylline (PTXF) on surfactant synthesis by isolated human type II pneumocytes. In order to isolate the pneumocytes, lungs obtained from both previously healthy multiple organ donors (n = 11) and patients who underwent surgical excision for lung cancer (n = 8) were used. Surfactant synthesis was measured by the incorporation of labeled glucose into the two most important phospholipid components of surfactant: phosphatidylcholine (PC) and phosphatidylglycerol (PGL). The pneumocytes of the donor group showed a greater degree of PC synthesis than those from the cancer group (3.44 +/- 0.19 versus 2.15 +/- 01.5 pmol/micrograms protein, p < 0.001). The synthesis of PC by pneumocytes in both the donor (1.13 +/- 0.19 versus 3.44 +/- 0.19 pmol/micrograms protein, p < 0.01) and cancer (0.99 +/- 0.11 versus 2.15 +/- 0.15 pmol/micrograms protein, p < 0.01) groups was decreased by TNF-alpha (100 ng/ml). This effect was blocked by PTXF (100 micrograms/ml), a substance that also increased PC production in the control-group pneumocytes from cancer patients, the final PC levels being similar to those of the donors in the absence of TNF-alpha. These results suggest that one of the mechanisms of TNF-alpha participation in the pathophysiology of ARDS is inhibition of surfactant synthesis, and support the hypothesis of in vivo production of TNF-alpha in lung-cancer patients, with subsequent chronic exposure of the lung epithelial cells to this cytokine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Bioequivalence study of nalidixic acid tablets: in vitro-in vivo correlation.

The USP dissolution test was used to select seven products with a wide range of dissolution characteristics for in vivo examination. The bioequivalence of seven (500 mg) products was evaluated in two crossover urinary excretion experiments. In each study three products were compared with the innovator product (Negram-Winthrop-Breon) in 12 subjects according to a 4 x 4 latin square design. Significantly different, lower bioavailability was observed in two products in relation to that of the innovator product. Linear in vitro-in vivo correlations were found between the cumulative amount excreted at 24 h and the log of the amount dissolved at 30 min and between log of the cumulative amount excreted up to 24 h and the log of the amount dissolved at 45 min.

Adult↗