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C Alonso

Publications and source records attributed to C Alonso.

At least 19 recordsLinked to original sources
PubMed1992

Platinum complexes of p- and m-aminobenzamidine. Synthesis, characterization, and cytotoxic activity.

Four platinum(II) aminobenzamidine complexes have been prepared and characterized by IR and 1H and 13C NMR spectroscopy, and tested for their ability to interact with the nicked and closed circular forms of the pUC8 plasmid DNA. The results show that the complexes of formula [Pt(LH)2Cl2]2X have a cis- geometry with an amino-Pt bonding, where L is either p- or m-aminobenzamidine and where 2X is 2Cl- or PtCl4(2-). It was observed that these complexes significantly alter the electrophoretic mobility of nicked and closed circular forms of DNA and that the alteration in electrophoretic mobility due to Pt(II)-p-aminobenzamidine binding is higher than that due to Pt(II)-m-aminobenzamidine. No difference in mobility was observed whether the DNA interacted with complexes having as counteranion Cl- or PtCl4(2-). The synthesized compounds were, in addition, assayed for antitumor activity in vitro against colon (CX-1), lung (LX-1), and mammary (MX-1) human tumor cells. The results show that these complexes inhibited the multiplication of the tumor cells and that they show higher specificity for lung cells.

Antineoplastic Agents↗
PubMed1992

Primary structure of neutral and acidic oligosaccharide-alditols derived from the jelly coat of the Mexican axolotl. Occurrence of oligosaccharides with fucosyl(alpha 1-3)fucosyl(alpha 1-4)-3-deoxy-D-glycero-D-galacto-nonulosonic acid and galactosyl(alpha 1-4)[fucosyl(alpha 1-2)]galactosyl(beta 1-4)-N-acetylglucosamine sequences.

Six major neutral and acidic oligosaccharide-alditols were prepared from the jelly coat of Mexican axolotl eggs. These compounds were demonstrated to contain 3-deoxy-D-glycero-D-galacto-nonulosonic acid (dNloA) and L-fucose (Fuc). The structures of the six major oligosaccharides were established as follows: [sequence: see text]

Ambystoma↗
PubMed1992

Comparative study of asparagine-linked glycans of plasma T-kininogen in normal rats and during acute inflammation.

Rat T-kininogen has been separated into two molecular variants by affinity chromatography on concanavalin A (ConA): a ConA-reactive (ConA+) and a ConA-non-reactive (ConA-) fraction, from which carbohydrate chains were quantitatively released by hydrazinolysis. On the basis of high-resolution 400 MHz 1H-n.m.r. spectroscopy of the re-N-acetylated hydrazinolysates, the carbohydrate structures of the two ConA molecular variants of rat T-kininogen were established. The ConA-non-reactive species contains a single type of carbohydrate chain with the following structure: [formula: see text] The ConA-reactive fraction contains the same structure and the following additional one: [formula: see text] The relative abundance of the two molecular forms is profoundly affected during inflammation (ratio ConA+/ConA-: 44% in normal and 95% in inflamed T-kininogen), but no structural modification of the carbohydrate chains was observed.

Animals↗
PubMed1992

Molecular characterization of a Leishmania donovani infantum antigen identified as histone H2A.

A Leishmania donovani infantum promastigote cDNA expression library was screened with a serum obtained from a dog naturally infected with this parasite. One of the positive clones obtained revealed nucleotide sequence similarities with the histone H2A genes from various organisms. Northern blot analyses and sequence data of three independently isolated cDNA clones indicated that the Leishmania H2A mRNAs are polyadenylated, as are the basal histone mRNAs of higher eukaryotes and the histone mRNAs of yeast. The analysis of the genomic distribution of the DNA coding for histone H2A suggested that, in L. d. infantum, there are at least four genes coding for the H2A protein. It is likely that there is a simultaneous expression of at least two of the H2A genes since differences in nucleotide sequence between two of the sequenced cDNAs were observed. Affinity-purified antibodies against the beta-galactosidase-fused H2A protein recognize specifically a Leishmania protein band with a molecular mass of 14 kDa.

Amino Acid Sequence↗
PubMed1992

Characterization of Le(x), Le(y) and A Le(y) antigen determinants in KDN-containing O-linked glycan chains from Pleurodeles waltlii jelly coat eggs.

Novel acidic oligosaccharides were isolated in large amounts by reductive alkaline treatment of the jelly coat of Pleurodeles waltlii (Michah) eggs. The oligosaccharides were found to contain the newly described KDN as acidic monosaccharide and possess either the Le(x), Le(y) and A Le(y) antigenic determinants. Occurrence of Le(x) and Le(y) determinants previously recognized as tumor-associated antigen (TAA) demonstrates that mucins of lower animals may represent a rich and easily available source for preparing TAA. Moreover, it reinforces the hypothesis according to which TAA are evolution markers.

Animals↗
PubMed1992

Malignant ovarian germ cell tumors: the experience at the Hospital de la Santa Creu i Sant Pau.

From 1979 to 1990, 33 patients with pathologically confirmed malignant ovarian germ cell tumors (MOGCT) were referred after initial surgical procedure at the Department of Oncology, Hospital de la Santa Creu i Sant Pau. The median age was 22 years (range, 10 to 39). Stage distribution was as follows: stage I, 12 patients; stage II, 6 patients; stage III, 11 patients; stage IV, 3 patients; and unstaged, 1 patient. The histologic diagnoses were 10 dysgerminomas, 4 endodermal sinus tumors, 11 immature teratomas, and 8 mixed germ cell tumors. Twenty-eight out of the thirty-three patients received postoperative chemotherapy with POMB-ACE-PAV or other platinum-containing regimens. One patient with stage IV disease failed to respond to chemotherapy and she died. Sixteen out of the twenty-eight treated patients had second-look laparotomy, which showed mature teratoma in six and persistent malignant teratoma in one patient. This last patient had complete remission with second regimen. No patient has developed recurrence. With a median follow-up of 66 months (range, 10 to 133), 32 patients (97%) are alive without evidence of disease. These data confirm that platinum-containing regimens have dramatically improved the prognosis for patients with MOGCT. This paper discusses primary chemotherapy and the role of the second-look in these patients.

Adolescent↗
PubMed1992

Palladium(II) salt and complexes of spermidine with a six-member chelate ring. Synthesis, characterization, and initial DNA-binding and antitumor studies.

By reaction of spermidine trihydrochloride with K2PdCl4 and PdCl2 at different pH's, we have synthesized the [sperH3]2[PdCl4]3 (I), [PdCl2(sperH)]2[PdCl4] (II), and [(PdCl2)3(sper)2] (III) compounds. The structure of these compounds was studied by IR and 1H NMR; complex II was analyzed by x-ray diffraction. In this complex the spermidine is attached to the PdCl2 group forming a six-member chelate ring with a protonated terminal amine group. The crystal of [PdCl2(sperH)]2[PdCl4] x 2H2O (II) is monoclinic, P2(1)/n, with a = 7.023(1) A, b = 12.662(1) A, c = 18.435(3) A, and beta = 99.95(1) degrees, Z = 4, R = 0.051, and Rw = 0.058 on the basis of 2690 independent reflections. We have compared the antitumor activity in vitro against the isolated human breast carcinoma MDA-MB 468 cell line of compounds I, II, and III with that of cis-diamminedichloroplatinum(II), cis-DDP. The results show that compounds III and III have values of ID50 similar (0.74 microgram/ml) or even lower (0.56 microgram/ml) than cis-DDP (0.80 microgram/ml). We also observed that compounds I, II, and III have the ability to induce conformational changes in covalently closed circular (ccc) form of the pUC8 plasmid DNA. Compounds II and III also induce conformational changes in the open circular (oc) form of this plasmid.

Antineoplastic Agents↗
PubMed1992

Regulation of hsp70 expression in Trypanosoma cruzi by temperature and growth phase.

The steady-state level of the hsp70 mRNAs of Trypanosoma cruzi cultured at different temperatures and growth conditions has been analyzed by Northern blotting. We show that only one size class of hsp70 mRNA, of about 2.2 kb, is transcribed from the hsp70 cluster and that its transcription is constitutive at 28 degrees C. However, after a heat shock treatment at 37 degrees C for 2 h of logarithmically growing parasites, the abundance of the hsp70 mRNA increased about 4-fold. A similar increase was observed at 28 degrees C when the parasite culture reached the stationary phase of growth. On the other hand, a heat shock at 42 degrees C did not change the steady state level of the 2.2-kb size class of hsp70 mRNA. However, accumulation of transcripts of high molecular weight was detected when stationary growing parasites were cultured at 42 degrees C for 2 h. Also at 37 degrees C the steady state level of the alpha- and beta-tubulin mRNAs of logarithmically growing parasites exhibited a slight increase but only after a period of 24 h. Analysis by one-dimensional immunoblots of the Hsp70 levels showed that at 37 degrees C the abundance of the protein was 4-fold higher than at 28 degrees C. Immunoblots of high-resolution two-dimensional gel electrophoresis showed, moreover, that various isoforms of this protein are constitutively expressed at 28 degrees C and that some of them have a specific pattern of induction at 37 degrees C. We observed, moreover, that the heat shock induces the expression of a series of proteins while it causes repression of others.

Animals↗
PubMed1992

Characterization of a highly repeated interspersed DNA sequence of Trypanosoma cruzi: its potential use in diagnosis and strain classification.

In the present paper we report the characterization of a repetitive DNA sequence from the genome of the Maracay strain of Trypanosoma cruzi. The sequence is 1025 nucleotides long and represent about 7% of the total nuclear DNA of the parasite with a copy number of 1-2 x 10(4) copies per genome. It is also present in a high copy number in several strains of T. cruzi but absent from other trypanosomatids and from the human genome. The DNA sequence is interspersed and present on many chromosomes. We show that the different copies of this repeat present extensive endonuclease restriction polymorphisms. Using 2 conserved oligonucleotide primers derived from the repetitive sequence, together with the polymerase chain reaction technique, the presence of less than 1/30 of a single parasite can be readily detected by ethidium bromide staining.

Animals↗
PubMed1992

[Importance of PCR in the diagnosis of hepatitis C].

The identification of hepatitis C virus, based on DNA amplification, gives a precise estimation of the prevalence of the most frequent agent of NANB hepatitis. The first ELISA allowing the detection of anti-HCV antibodies, had too many false positive results and required the development of more sensitive and specific assays to confirm its results. PCR, allowing the hepatitis C virus diagnosis by showing directly HCV RNA sequences, offers a complementary approach to immunoserological tests. In blood donors with anti-HCV antibodies and with indeterminate or negative confirmatory tests, the finding of HCV RNA sequences reveals serum infectivity. During acute hepatitis, the delay in the appearance of anti HCV hampers acute phase diagnosis. The early detection of HCV RNA in peripheral blood, confirms the diagnosis and opens up therapeutic possibilities. In chronic hepatitis, the diagnosis of seronegative forms may only be resolved by PCR. Moreover, the presence of HCV RNA in peripheral blood represents the only marker of on-going viral replication and coincides with the severity of liver damage. During treatment with interferon, the follow up of HCV RNA sequences makes it possible to monitor its efficacy. The search for HCV RNA sequences directly in liver tissue shows that HCV may replicate in the liver in the absence of viremia. The presence of HCV RNA in the liver and the serum of liver transplanted patients is essential for the etiological diagnosis and management of hepatitis and bone marrow failure occurring after transplantation. Epidemiological study using PCR is a major tool in documenting vertical transmission between mother and child. Finally, PCR is important for the analysis of the HCV genome. Thus, in France there are at least three main strains, one close to the US prototype, the other close to the Japanese strain, possibly responsible for a more severe illness and a third one distinct from the previous two. However, its limits and constraints imply that PCR must not be considered as a routine assay. This emphasizes the need for more simple and rapid diagnostic tests, allowing the detection of HCV antigens and, as in hepatitis B, the progressive unravelling of the life cycle of HCV.

Animals↗
PubMed1992

Species of Pseudomonas obtained at 7 degrees C and 30 degrees C during aerobic storage of lamb carcasses.

A total of 268 strains of Pseudomonas isolated during storage life of lamb carcasses was identified to species level. One-hundred and thirteen strains obtained at 30 degrees C were Ps. fragi (51), Ps. lundensis (17), Ps. fluorescens biovars I (10), III (9) and VI (1), Ps. putida biovar A (8 strains) and unidentified (17 strains). Species and biovars isolated at 7 degrees C (155) were Ps. fragi (101), Ps. lundensis (32), Ps. fluorescens biovar I (6), Ps. putida biovar A (8) and unidentified (8). Numerical analysis (82% SSM, UPGMA) of 'psychrotrophic' and 'mesophilic' strains resulted in the formation of nine and eight clusters respectively. The dendrograms obtained exhibited similar structures. Most of the strains of Ps. lundensis and Ps. fragi clustered together. Strains of this latter species also joined the type strain of Ps. testosteroni and appeared included with phenons containing the Ps. putida strains. There were clusters made up exclusively of strains assigned to one biovar or group (Ps. fluorescens biovars I and II and unidentified). A high level of similarity was observed between clusters of Ps. fluorescens biovar I and those containing the Ps. fragi-Ps. lundensis complex (> 74% SSM) and Ps. lundensis (> 80%). The recovery of pseudomonads seemed to be affected by the sampling day.

Aerobiosis↗
PubMed1992

External and interstitial radiation therapy of locally advanced carcinoma of the breast.

The present report concerns 164 cases of locally advanced breast cancer (stage III), treated between December 1977 and January 1987. The local therapy consisted exclusively of radiation therapy including external beam irradiation (60Co) up to 45-50 Gy supplemented with a boost, delivered either by interstitial 192Ir (30-40 Gy) or by external irradiation from limited fields (15-22 Gy). Eighty-one patients also received adjuvant systemic chemotherapy. A total of 51 local failures (31%) occurred. The actuarial rate of survival with local tumor control was 53% at 5 years and 49% at 6.5 years. A total of 69 patients developed distant metastases (42%). The actuarial survival without distant failure was 43% at 5 years and 37% at 6 years. The actuarial survival rate at 5 years was 53% and 38% at 7 years. The cosmetic results were excellent in 58 patients and poor in 13 patients (9.7%). The result suggests that stage III breast cancer can be satisfactorily treated with radiation therapy alone as local treatment.

Adult↗
PubMed1992

MHC class I antigen expression is inversely related with tumor malignancy and ras oncogene product (p21ras) levels in human breast tumors.

MHC class I antigens participate in the immune response by presenting peptides to CD8+ cytotoxic T cells. Decreased expression of these antigens in tumor cells may contribute to an evasion of immune system and consequently to enhanced tumor growth. However, not all tumors expressing low levels of HLA antigens show increased malignancy, probably as a result of the differential activity of the oncogenes involved in malignant transformation. The ras family of cellular oncogenes is one of the most frequently detected families of transformation-inducing genes in human solid tumors. The aim of this work is to study the expression of MHC antigens and the ras oncogene product, p21ras, in 60 primary breast tumors in order to define its clinical significance in tumor progression. HLA antigen expression and p21ras levels were measured on breast tumors using immunohistochemistry methods and enzymoimmunoassay, respectively. The results demonstrate that more invasive tumors have both a decreased expression of HLA class I antigens and higher levels of p21ras protein expression than less aggressive tumors. These findings indicate that the capacity of breast cancers to grow and metastasize is related to low levels of MHC class I antigens and enhanced p21ras expression, thus supporting the involvement of MHC and ras oncogenes in breast tumor malignancy.

Breast Neoplasms↗
PubMed1992

[Evaluation of two commercial kits for detection of Helicobacter pylori specific antibodies in patients undergoing gastroscopy. A seroprevalence study in an asymptomatic population].

BACKGROUND: We evaluate two different commercially available kits for detecting specific antibodies against Helicobacter pylori in a group of 48 patients with gastrointestinal symptoms that underwent an endoscopic procedure. We also study the seroprevalence of anti-H. pylori antibodies in asimptomatic individuals from our area. METHODS: Microbiologic and pathologic studies were performed in 48 gastric biopsies, in relation with antibodies detection using ELISA (Pylori stat test, Whittaker) and latex particles agglutination (Pyloriset, Orion). We also used ELISA tests for determining the seroprevalence of H. pylori antibodies in 139 asimptomatic individuals. RESULTS: Ninety-four percent of patients with peptic ulcer disease and 81% of patients without peptic ulcer disease but complaining of dyspepsia were infected by H. pylori. None of the patients with normal gastric mucosae was found to be infected. Sensitivity and specificity of ELISA test were 100% and 73%. Latex test sensitivity and specificity were 46% and 82%. The seroprevalence of antibodies among healthy individuals in our area increases with age (19% among children under 9 years of age) and reaches a peak at 40-49 years of age (84%), with a mean value of 60% in all ages' groups. CONCLUSIONS: There is a high correlation between Helicobacter pylori infection and gastric mucosa alterations. The ELISA test is best correlated with other laboratory data used for defining infection. The seroprevalence of H. pylori antibodies is also high, and therefore we recommend that the use of serologic diagnostic test must be highly selective.

Adolescent↗
PubMed1992

[The duration of the effect of norfloxacin on the fecal flora in cirrhosis patients].

The aim of the study has been to assess if intermittent treatment with norfloxacin could be able to maintain selective intestinal decontamination in cirrhotic patients in order to prevent bacterial infections. Group I (n = 10, subgroup Ia, n = 5, hospitalized cirrhotics, subgroup Ib, n = 5, outpatient cirrhotics) received 400 mg/24 h norfloxacin 7 days. Group II (n = 5, outpatient cirrhotics) received 400 mg/12 h norfloxacin 7 days. Gram-negative aerobic bacilli of the fecal floral were strongly suppressed in all patients at the end of the treatment, and they totally (Group I) or partially (Group II) recovered the initial concentrations 7 days after the end of the treatment. There were not significant differences between subgroups Ia and Ib. These results suggest that prophylactic treatment with norfloxacin in cirrhotic patients at high risk of infection should be continuous during the period in whom patients must be submitted to selective intestinal decontamination.

Administration, Oral↗
PubMed1991

Characterization and 400-MHz 1H-NMR analysis of urinary fucosyl glycoasparagines in fucosidosis.

Fucosyl glycoasparagines accumulating in the urine of a patient with fucosidosis were isolated using reverse-phase HPLC. Structural analysis of 25 glycoasparagines was carried out by combination of methylation and 400-MHz 1H-NMR spectroscopy analyses. The compounds represent different steps in the incomplete catabolism of N-glycosidically linked glycans, as the result of an alpha-L-fucosidase deficiency. All of the glycoasparagines possess a fucose residue alpha-1,6-linked to the GlcNAc 1 residue attached to asparagine. Fucose residues on the peripheral branches were linked either alpha-1,3 to GlcNAc residues (X determinant) or alpha-1,2 to galactose residues (H determinant). The present study allows precise assignments of the NMR parameters for most of the fucosyl linkages occurring in N-glycosidically linked glycans of the N-acetyllactosamine type.

Carbohydrate Sequence↗