Biomedical subjects

R Ortiz

Publications and source records attributed to R Ortiz.

At least 19 recordsLinked to original sources

PubMed2008

Treatment of pediatric non-Hodgkin lymphomas in a country with limited resources: results of the first national protocol in Nicaragua.

We report the results of a protocol for the diagnosis and treatment of pediatric non-Hodgkin lymphomas (NHL) conducted in Nicaragua in the context of an international collaborative program. Fifty-three children with NHL treated between 1996 and 2003 were retrospectively evaluated. Therapy was designed based on local drug availability and affordability with dose and schedule adaptations for Burkitt and lymphoblastic lymphomas. With a median follow-up of 3 years, the projected 9-year overall survival was 63% and event-free survival 53%. The treatment was efficacious, feasible, and well tolerated in spite of the local socio-economical conditions.

Adolescent↗

PubMed2006

Fine structural and cytochemical analysis of the processes of cell death of oocytes in atretic follicles in new born and prepubertal rats.

The process of cell death of oocytes was studied in atretic ovarian follicles of rats aged from 1 to 28 days using light and electron microscope and cytochemical methods. These methods were TUNEL procedure for DNA breaks, active caspase-3 and lysosome-associated membrane protein 1 (LAMP-1) immunolocalizations. The structural features of the process of oocyte death are mainly characterized by the presence of abundant clear vacuoles and autophagosomes, as well as by the absence of large clumps of compact chromatin associated to the nuclear envelope and apoptotic bodies. These features are common to oocytes in all types of follicles studied. Cytochemical features consisting in positive reactions to TUNEL method, active caspase-3 and LAMP-1 immunolocalizations, are common to the cell death of oocytes in all types of follicles. Particular features of the process of cell death of oocytes are found in different types of follicles. Two morphological patterns of cell death occur in pre-follicular oocytes of the new born and in primordial follicles in 1 to 5 days old rats. One is distinguished by clear nucleoli and moderate compaction of chromatin in clumps frequently resembling meiotic bivalents. The second pattern is characterized by nucleolar condensation and by the absence of compact chromatin. The process of cell death of oocytes in antral follicles is characterized by ribonucleoprotein ribbon-like cytoplasmic structures, pseudo-segmentation, and loss of contact with granulosa cells.

Age Factors↗

PubMed2005

Antibacterial studies, DNA oxidative cleavage, and crystal structures of Cu(II) and Co(II) complexes with two quinolone family members, ciprofloxacin and enoxacin.

Nine coordination compounds of Cu(II) and Co(II) with Ciprofloxacin (HCp) and Enoxacin (HEx) as ligands have been prepared and characterized. Single crystal structural determinations of [Cu(HCp)2(ClO4)2].6H2O (1) and [Co(HEx)2(Ex)]Cl.2CH(3)OH.12H2O (4) are reported. The crystal of 1 is composed of [Cu(HCp)2(ClO4)2] units with the two perchlorate anions semicoordinated, and uncoordinated water molecules. The copper ion, at a crystallographic inversion centre, is in a tetragonally distorted octahedral environment. The structure of 4 consists of cationic monomeric [Co(HEx)2(Ex)]+ units, chloride anions, and uncoordinated methanol and water molecules. The complex is six-coordinate, with a slightly distorted octahedral environment around the metal centre. Some complexes of ciprofloxacin and enoxacin were screened for their activity against several bacteria, showing activity similar to that of the corresponding free ligands. All compounds tested were more active against Gram-negative bacteria than against Gram-positive bacteria. Ciprofloxacin hydrochloride and its complexes were more active than enoxacin and its complexes. In addition, the bactericidal studies against Staphylococcus aureus ATCC 25923 reveal that one complex exhibits the "paradoxical effect" (diminution in the number of bacteria killed at high drug concentration), which has been described and related to the mechanism of action of quinolones, but three other complexes do not, suggesting different mechanisms of bactericidal action. The ability of Cu(HCp)2(NO3)2.6H2O to cleave DNA has been determined. The results show that the complex behaves as an efficient chemical nuclease with ascorbate/hydrogen peroxide activation. Mechanistic studies using different inhibiting reagents reveal that hydroxyl radicals are involved in the DNA scission process mediated by this compound.

Anti-Infective Agents↗

PubMed2005

Voriconazole therapeutic drug monitoring in allogeneic hematopoietic stem cell transplant recipients.

Voriconazole, a new antifungal agent, is increasingly being used after HSCT. The hepatic cytochrome P450 isoenzyme 2C19 plays a significant role in voriconazole metabolism. As CYP2C19 exhibits significant genetic polymorphism, some patients metabolize voriconazole poorly resulting in increased plasma drug levels. The clinical significance of this is unknown, and the utility of monitoring voriconazole levels is unclear. Steady-state trough plasma voriconazole levels were obtained in 25 allogeneic HSCT recipients using an HPLC assay. Patients had drug levels checked once (n=13), twice (n=10), or > or =3 times (n=2) 5-18 days (median 10) after starting voriconazole or dose modification. The 41 voriconazole levels were 0.2-6.8 microg/ml (median 1.6); 6 (15%) were <0.5 (possibly below the in vitro MIC90 for Aspergillus spp.). Voriconazole concentrations correlated with aspartate aminotranferase (AST) (r=0.5; P=0.0009) and alkaline phosphatase (r=0.34; P=0.03), but not with creatinine, bilirubin and alanine aminotransferase (ALT). Since liver dysfunction is common after HSCT, it was not possible to determine if elevated AST and alkaline phosphatase levels were the cause or the consequence of higher voriconazole levels. We conclude that trough voriconazole levels vary considerably between patients, and suggest monitoring levels in patients receiving voriconazole for confirmed fungal infections, and in those with elevated AST or alkaline phosphatase levels.

Alkaline Phosphatase↗

PubMed2004

Transmission of a cyclical translocation in two cranberry cultivars.

The occurrence of cyclical translocation involving three non-homologous chromosomes and affecting pollen stainability has been observed in two cranberry cultivars: Howes, and Wilcox, a progeny of Howes. These cultivars were crossed with six normal cranberry cultivars to study the transmission of the cyclical translocation to their progeny. The translocational progeny were determined by pollen tetrad analysis. A total of 102 individuals (6 crosses) were analyzed in the progeny of Wilcox and 116 individuals (5 crosses) in the progeny of Howes. The ratios observed in the progeny of Wilcox and Howes were 71 translocated: 31 normal, and 79 translocated: 37 normal, respectively. The segregations deviated from the expected 1 translocated: 1 normal progeny ratio, but fit either a 3:1 or 2:1 ratio. The altered segregations may indicate the presence of a balanced lethal system located in the translocated segments of both Howes and Wilcox. Sterile individuals were found in the progeny of WilcoxxHowes, which could indicate that the two parents have non-identical translocations. The translocated progeny of both cultivars had a normal distribution for pollen stainability, which indicated that both the occurrence of crossing over in the interstitial region and the segregation of chromosomes are under polygenic control.

Chromosome Segregation↗

PubMed2003

Fine structural cytochemical analysis of homologous chromosome recognition, alignment, and pairing in Guinea pig spermatogonia and spermatocytes.

The nuclei of guinea pig spermatogonia and spermatocytes were studied by means of quantitative autoradiography and electron microscopic methods such as high-resolution cytochemistry, immunocytochemistry, and in situ hybridization. Our observations reveal, in the nucleus of spermatogonia type B, small lampbrush structures of extended chromatin not found in nonmeiotic cells. During meiotic interphase, pairs of parallel lampbrush structures become associated by numerous filaments. The formation of the synaptonemal complex is simultaneous with the extension of chromosomal axes in a continuous leptotene-zygotene stage. Some chromosomes do not recognize their homologs before the onset of the leptotene-zygotene stage and undergo classical leptotene and zygotene stages. The immunocytochemical localization of Dmc1 and Rad51 supports the idea that these proteins are not involved in homology search and final pairing. Immunolocalization of DNA, RNA polymerase II, heterogeneous nuclear ribonucleoproteins, small nuclear ribonucleoproteins, and the trimethyl-guanosin cap of small nuclear RNAs suggests that the chromatin of lampbrush structures transcribe hnRNA and that splicing is scarce. The results of quantitative autoradiography after [3H]uridine labeling show an intense transcription accompanied by a very slow export of RNA. In situ hybridization demonstrates the presence of RNA in the regions of homology recognition and pairing. These results lead us to propose that the RNA synthesized in the lampbrush structures is involved in the process of homology searching and recognition.

Adenosine Triphosphatases↗

PubMed2003

Ultrastructural and immunocytochemical analysis of the XY body in rat and Guinea pig.

The formation of the XY body involves the compaction of the extended chromatin to form a mesh of fibrogranular structures. During this process the ribonucleoprotein particles (RNP), which were associated with the chromatin filaments progressively disappear. High resolution immunolocalization indicates that the mature XY body does not contain RNA polymerase II, hnRNPs, or snURNPs. Occasionally chromatin fibrils extend outside of the XY body. These fibrils are frequently associated with nascent RNP fibrils and granules indicating that not all the DNA of the sex chromosomes is transcriptionally inactive. However, transcription is located outside the sex body. The recombination protein Dmc1 is present in nodules associated with the unpaired chromosomal axes of the sex chromosomes located in the XY body. Cytochemical staining methods and in situ hybridization at electron microscopic level show that RNA is present in the unpaired chromosomal axes suggesting that the presence of RNA in the chromosomal axes and in forming synaptonemal complexes is related with the process of final pairing. The sex body and the nucleoli associated with it do not interweave and do not exchange RNA or DNA-containing filaments. These observations indicate that the spatial relation between these structures is just a close proximity, which is, however, very frequent.

Animals↗

PubMed2002

Analysis of potential duplicates in barley gene bank collections using re-sampling of microsatellite data.

Redundant duplication among putative Nordic spring barley material held at 12 gene banks worldwide was studied using 35 microsatellite primer pairs covering the entire barley genome. These microsatellite markers revealed an average of 7.1 alleles per locus, and a range of 1 to 17 different alleles per locus. Similarity of accession name was initially used to partition the 174 repatriated accessions into 36 potential duplicate groups, and one group containing 36 apparently unique or unrelated accessions. This partitioning was efficient to produce a distribution of mainly small average genetic distances within potential duplicate groups compared to distances from the group of unique accessions. However, comparisons within potential duplicate groups still contained large genetic distances of the same size as distances between unique accessions indicating classification errors. A bootstrap approach based on re-sampling of both microsatellite markers and alleles within marker loci was used to test for homogeneity within potential duplicate groups. The test was used in each group for sequential elimination of accessions with a significantly large average genetic distance to identify a homogeneous group. Such genetically homogeneous groups of two or more accessions were identified in 22 among the 36 potential duplicate groups studied. Results from the genetic analysis of some potential duplicate groups supported previous conclusions based on passport data through inclusion of the historically most-original accession in the genetically homogeneous group. In other potential duplicate groups the apparently most-original accession according to passport data was not included in the homogeneous set of accessions, indicating that this most-original accession does not have duplicate accessions in the group. During the present study the largest average genetic distance accepted in any homogeneous group was smaller than the smallest distance declared significant in any group, with a threshold average genetic distance of approximately 0.14. The results are discussed with respect to the identification of duplicate accessions within potential duplicate groups, as well as the elimination of genetic off types in such groups. Furthermore, large barley gene bank collections may be screened for potential duplicates with genetic distances below the suggested threshold of 0.14.

Gene Library↗

PubMed2002

Interactions of metal ions with two quinolone antimicrobial agents (cinoxacin and ciprofloxacin). Spectroscopic and X-ray structural characterization. Antibacterial studies.

Several novel metal-quinolone compounds have been synthesized and characterized by analytical, spectroscopic and X-ray diffraction methods. The crystal structure of the four compounds, Na(2)[(Cd(Cx)3)(Cd(Cx)3(H2O))].12H2O, [Co(Cp)2(H2O)2].9H2O, [Zn(Cp)2(H2O)2].8H2O and [Cd(HCp)2(Cl)2].4H2O, is presented and discussed: HCx=1-ethyl-1,4-dihydro-4-oxo(1,3)-dioxolo(4,5-g)cinnoline-3-carboxylic acid and HCp=1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid. In all these compounds the quinolone acts as a bidentate chelate ligand that binds through one carboxylate oxygen atom and the exocyclic carbonyl oxygen atom. Complexes of ciprofloxacin were screened for their activity against several bacteria, showing activity similar to that of the ligand. In addition, the number of bacteria killed after 3 h of incubation with the ligand, [Co(Cp)2(H2O)2].9H2O, Ni(Cp)2.10H2O and Cu(Cp)2.6H2O, was determined against S. aureus ATCC25923. There is a direct relationship between the growth rate and the lethal rate. Against growing bacteria, the ligand is the most bactericidal and Cu(Cp)2.6H2O is the less bactericidal. On the contrary, against non-dividing bacteria, the complexes were more bactericidal than the ligand, with Cu(Cp)(2).6H(2)O the most bactericidal compound.

Anti-Infective Agents↗

PubMed2002

Hydrogen peroxide-induced DNA damage and DNA repair in lymphocytes from malnourished children.

The aim of this study was to assess DNA repair capacity in lymphocytes of children with protein calorie malnutrition using the single-cell gel electrophoresis (comet) assay. Repair capacity was assessed by estimating the relative decrease of DNA migration length 5, 15, 30, and 60 min after hydrogen peroxide treatment, in three groups of children: well-nourished (WN), well-nourished infected (WN-I), and malnourished infected (MN-I). In addition, the DNA migration length was evaluated in all groups before and after peroxide treatment. Comparison of mean migration lengths observed in WN and WN-I children showed significant differences at all times tested; between WN-I and MN-I differences were also observed, except after hydrogen peroxide exposure. This implies that lymphocytes of WN-I and MN-I children were equally sensitive to hydrogen peroxide. Nevertheless, the MN-I group clearly shows the greatest overall percentage of damaged cells at all times tested. In relation to repair capacity, at 5 min it was approximately 30% in both groups of well-nourished children, but only 20% in MN-I; 15 min after exposure, repair capacity increased to 51% in well-nourished children but only to 31% in MN-I; and at 60 min this capacity increased to 82% in well-nourished but only to 55% in MN-I. These data indicate that lymphocytes of malnourished children show a decreased capacity to repair hydrogen peroxide-induced DNA damage compared to that of well-nourished controls. This reflects that only malnutrition is associated with decreased DNA repair capacity. Additionally, the data confirm that severe infection and malnutrition are two factors clearly associated with increased DNA damage.

Case-Control Studies↗

PubMed2002

Inbreeding and true seed in tetrasomic potato. III. Early selection for seedling vigor in open-pollinated populations.

Tuber yield in open-pollinated (OP) offspring of potato cultivars appears to be correlated with the proportion of hybrids within each population. OP true potato seed (TPS) from ten selected clones was tested in an experiment at two Peruvian locations, San Ramón (mid-altitude warm tropics) and Huancayo (highland cool tropics), to investigate the early selection effect on OP populations. Another experiment in La Molina (dry coast) was included to confirm the results from these other two locations. The results clearly showed that plant survival, tuber yield and berry number can be increased by a strong early selection. Likewise, the results suggested that the most-promising OP offspring for TPS production could be derived from tetraploid clones with a high rate of outcrossing. This experiment demonstrates that high tuber yield may be obtained in OP TPS cultivars with little effort, using early selection for seedling vigor in the nursery. Genetic interpretation of this response to early selection indicates that both the intensity of selection and non-additive genetic variation for tuber yield account for these observed gains.

Journal Article↗

PubMed2002

Inbreeding and true seed in tetrasomic potato. IV. Synthetic cultivars.

A true potato seed (TPS) synthetic cultivar from open pollination may broaden the genetic base in potato. A synthetic cultivar can also reduce the effect of inbreeding and maintain the productivity from generation to generation. Selected tetraploid parental genotypes, based on combining-ability tests, were chosen for isolated polycrosses to obtain tetraploid offspring. A series of experiments were undertaken to investigate the development of these TPS synthetic populations in two Peruvian locations: San Ramon, a rainfed, humid, mid-altitude environment, and La Molina, an arid, coastal environment under irrigation. Natural open-pollinated synthetics or control-mixture synthetics, involving two to six parents, had a similar tuber set but plant survival and tuber weight were higher in control synthetics including two or six parents. The results suggest that two-parent open-pollinated TPS synthetics may be a feasible option by selecting the right parents for the base population. A subsequent experiment showed that four-parent control synthetics (i.e. double crosses) were the best for tuber weight and size, followed by the two-parent control synthetics. Synthetic breeding populations could be shared with other breeders, who in cooperation with their local farmers may select promising genotypes for further cultivar release.

Journal Article↗

PubMed2002

Structure and regulation of expression of the mouse GH receptor.

GH-binding protein (GHBP) in the mouse consists of a ligand-binding domain, which is identical to the extracellular portion of the GH receptor (GHR), and a hydrophilic C-terminal domain, in place of the transmembrane and intracellular domains of the GHR. The two proteins are encoded by separate mRNAs which are derived from a single gene by alternative splicing. Determination of the gestational profiles of GHR and GHBP mRNA expression in mouse liver and placenta shows that in the liver, the 1.4 kb mRNA corresponding to the mouse GHBP increases approximately 20-fold between non-pregnant and late pregnant mice, whereas the relative increase in the expression of the 4.2 kb mouse GHR was 8-fold. The rise in the steady-state levels of both mRNAs began on day 9 of gestation. Mouse GHBP mRNA levels continue to rise until day 15 of pregnancy, while GHR mRNA abundance reaches a plateau by day 13. By elucidating the temporal changes in GHR and GHBP mRNA abundance during pregnancy and lactation in multiple maternal tissues and by assessing the ontogeny of these mRNAs in fetal and early postnatal mouse liver, our studies have demonstrated that the alternative splicing of mouse GHR/GHBP mRNA precursor is regulated in a tissue-, developmental stage- and physiological state-specific manner. In vitro studies using hepatocytes in culture have begun to elucidate the hormonal factor(s) involved in the gestation control of the expression of GHR and GHBP. Treatment of hepatocytes with GH or estradiol (E2) alone did not have any effect on the cellular concentrations of GHBP and GHR. However, the combination of E2 and GH up-regulated the cellular concentrations of GHBP and GHR 2- to 3-fold. GHBP and GHR mRNA concentrations were also up-regulated 2- to 3-fold. ICI 182-780, a competitive inhibitor of E2 for the estrogen receptor (ER), at different concentrations inhibited the E2- and GH-induced stimulation of GHBP and GHR. Furthermore, ER concentrations increased 5- to 7-fold in hepatocytes treated with E2 and GH compared with those in untreated cells or cells treated with either E2 or GH alone. Our studies in the mouse suggest that GHBP is an important cell-surface receptor for GH in the liver. These studies postulate that an arginine-glycine-aspartic acid sequence found on mouse GHBP but absent in other species is responsible for the association of GHBP with the plasma membrane by binding to one or more integrins on the surface of liver cells.

Animals↗

PubMed2002

Cytochemical study of the distribution of RNA and DNA in the synaptonemal complex of guinea-pig and rat spermatocytes.

The distribution of DNA and RNA in the synaptonemal complex and related structures, was studied using high resolution cytochemical methods and in situ hybridization, in guinea pig and rat testis. Serial sectioning demonstrates that frequently the formation of the synaptonemal complex (SC) occurs without a previous development of isolated chromosomal axes. The lateral elements of the forming SC are in continuity with pairs of DNA-containing thin filaments. These chromatin filaments fold in numerous short loops just before incorporating to the lateral elements. Some of these loops are included in the ribbon-like structure of the lateral elements of the mature SC. We propose that these short loops contain the DNA attachment sequences associated with the proteins of the LE. During the formation of the SC one of the two chromatin filaments incorporates at the central surface of the forming lateral element (LE) and the other is located at the external side of the LE. This unexpected distribution does not correspond to the pair of thick filaments previously discerned in structure of the LE. The presence of RNA associated with the DNA-containing thin filaments, as well as with the axial chromatin elements of the forming SC, may be related with the transcription occurring during meiotic prophase, specially during zygotene stage. We propose that RNA is involved in a still uncharacterized process essential for pairing.

Animals↗

PubMed2002

Bioavailability of two metamizole (dipyrone) solutions as single doses of 2 g versus metamizole capsules.

OBJECTIVE: The aim of this study was to investigate the extent and the rate of absorption of metamizole, appearing in blood as methylaminoantipyrine (MAA), from a new oral solution and a parenteral solution administered by the oral route relative to capsules. METHODS: An open, randomized, 3 single-dose (2 g metamizole), crossover study with intervals of 7 days between periods was performed in 19 male and female healthy volunteers (age 22 - 45 years, body weight 49 - 88 kg, body height 156 - 189 cm). Metamizole metabolites were measured with an HPLC technique. The test formulations were considered bioequivalent with the reference formulation if the 90% confidence limits of the AUC0-->infinity and Cmax ratios and the tmax differences were within the range of 80 - 125%. RESULTS: The 90% confidence limits of the comparisons between capsules (reference) and oral solution, capsules (reference) and ampoules, and ampoules (reference) and oral solution were 98.5 - 117.8, 99.5 - 132.6 and 81.3 - 105.8 for AUC0-->infinity 98.7 - 119, 101.7 to 129.2, and 82.1 - 104.8 for Cmax, and 84.4 to 115.6, 100 - 105.6 and 70.3 - 100 for tmax, respectively. CONCLUSION: The oral solution was bioequivalent to capsules with regard both to the extent and the rate of MAA absorption. Metamizole as oral solution was bioequivalent to reference ampoules in the extent of MAA absorption, but absorption rate was faster. Ampoules showed a higher MAA bioavailability than capsules.

Administration, Oral↗

PubMed2002

Susceptibility to DNA damage induced by antibiotics in lymphocytes from malnourished children.

Infectious disease and malnutrition in children are public health problems in developing countries. Malnutrition is associated with higher levels of DNA damage, and this increased damage could be due to different factors, including the possibility that cells from malnourished children could be more susceptible to environmental damage. The aim of the present study was to evaluate the susceptibility of lymphocytes from malnourished children to DNA damage induced by antibiotics by using the comet assay. The same group of malnourished infected children were studied before and after a treatment period, and compared to a group of well-nourished infected children. Results showed that before and after drug treatment, tail length migration was two times greater in malnourished than in well-nourished children. The proportion of cells with high damage was also increased in malnourished children. Additionally in well-nourished and malnourished children, a cell subpopulation (non-damaged cells) more resistant to DNA damage induced by antibiotics was observed; this was more prevalent in the well-nourished children. Meanwhile, in malnourished children, a cell population seems to be more susceptible and reaches higher levels of DNA damage. This might help explain the impaired immune response observed in malnourished children. The increased DNA migration and the increased proportion of cells with higher levels of damage seem to indicate that malnourished children are more susceptible to DNA damage induced by drugs.

Anti-Bacterial Agents↗

PubMed2001

Assessment of DNA damage in spleen, bone marrow, and peripheral blood from malnourished rats by single cell gel electrophoresis assay.

Severe malnutrition is widely distributed throughout the world and exhibits a high prevalence in developing countries. Experimental malnutrition models have been useful to study the effects of malnutrition at early ages. The purpose of this study was to determine if severe malnutrition induced during lactation in rats increases DNA damage in spleen, peripheral blood, and bone marrow cells, as well as in isolated lymphocytes or lymphoid cells from the same tissues. These cells were obtained from malnourished rats at weaning (21 days of age). DNA damage was estimated by using the alkaline single cell electrophoresis assay. The results obtained in this study indicate that malnutrition is associated with a significant increase in DNA damage in all cell types that were studied in malnourished rats. The analysis of the length of DNA migration and dispersion coefficient showed that some cell types were more susceptible to DNA damage related with malnutrition. The damage observed could be due to the deficiency of several essential nutrients required for protein synthesis that are associated with DNA integrity, impaired DNA repair mechanisms, and/or to the unavailability of molecules necessary to protect the cells against DNA oxidative damage. This damage may produce negative effects for the further development of the organism, since bone marrow is the main site of hematopoiesis and spleen is an important lymphopoietic organ. Also, the increased level of DNA damage in peripheral blood lymphocytes and leukocytes could be related to negative effects such as a deficient immune response.

Animals↗

PubMed2001

[Pilot study with the monoclonal antibody IOR-C5 as a potential agent of radioimmunoscintigraphy in colorectal cancer].

UNLABELLED: IOR C-5 is a G1 immunoglobulin type intact murine monoclonal antibody (MAb) that was developed in the Center of Molecular Immunology in Havana City, Cuba. In immunohistochemical studies, this demonstrated a significant affinity for the epithelial tissues so that it was used in a pilot clinical study to perform a radioimmunoscintigraphy of the colorectal primary tumors and their locoregional recurrences. It was labeled with 99mTc using the Schwarz method, with a > 95% performance. Planar images of the chest, abdomen and pelvis were performed at 10 minutes, 4-6 hours and 18-24 hours post-injection in the anterior and posterior projections and the SPECT was performed 4-6 hours and 18-24 hours post-injection of 1.85 GBq 99mTC. This study has aimed to verify in vivo the capacity of ior-C5 MAb to accumulate in the malignant colorectal lesions. ior-C5 accumulated in 5 out of the 7 patients who were studied and who were suffering from colorectal cancer or in whom there was suspicion of recurrence. There was a negative case of primary tumors, which was an adenocarcinoma in situ in a tubular-papillary adenoma. The second case with a negative radioimmunoscintigraphy was a true negative case. CONCLUSIONS: It can be concluded that even though the number of patients is quite low, ior-C5 fulfilled the expectations of recognizing the epitope expressed in colorectal tumors in an in vivo human environment.

Adenocarcinoma↗