Social Appropriation of Knowledge About Research in Prostate Cancer with Middle Education Students in Three Colombian Cities

In Colombia, prostate cancer (PCa) is the most common cancer for incidence and mortality in men, which turns it into a public health problem. For high-risk communities to better understand the usefulness of basic research about PCa, a strategy of social appropriation of knowledge (SAK) in science and cancer was designed and implemented. A pedagogical activity and two tests (a pre-test and a post-test) were applied to middle education students in four schools in three Colombian cities to identify previous knowledge of biology concepts and cancer perceptions. As for biology concepts, there was a statistically significant increase (p < 0.01) in the total results of all questions in the post-test, especially in items related to the structure of DNA, differences between RNA and DNA, and codon. Similarly, better success rates were observed in questions about replication and mutation, and a statistically significant improvement related to the definition of cancer, cancer prevention, and its association with culture or ethnicity (p < 0.01). The results of the open question show what students learned about or were interested in the most, as evidence of the exchange of knowledge in those cities and the social appropriation of knowledge about PCa in Colombia. These findings show that this type of intervention, in diverse social contexts, is essential to improve understanding and perceptions that link school and scientific knowledge to a real problem, such as health and, in this case, cancer.

Metabolic pathways enriched according to ERG status are associated with biochemical recurrence in Hispanic/Latino patients with prostate cancer

BACKGROUND

The role of ERG-status molecular subtyping in prognosis of prostate cancer (PCa) is still under debate. In this study, we identified differentially expressed genes (DEGs) according to ERG-status to explore their enriched pathways and implications in prognosis in Hispanic/Latino PCa patients.

METHODS

RNA from 78 Hispanic PCa tissues from radical prostatectomies (RP) were used for RNA-sequencing. ERG_high /ERG_low tumor groups were determined based on the 1.5-fold change median expression in non-tumor samples. DEGs with a False Discovery Rate (FDR) < 0.01 and a fold change >2 were identified between ERG_high and ERG_low tumors and submitted to enrichment analysis in MetaCore. Survival and association analyses were performed to evaluate biochemical recurrence (BCR)-free survival.

RESULTS

The identification of 150 DEGs between ERG_high and ERG_low tumors revealed clustering of most of the non-BCR cases (60%) into de ERG_high group and most of the BCR cases (60.8%) in ERG_low group. Kaplan-Meier survival curves showed a worst BCR-free survival for ERG_low patients, and a significant reduced risk of BCR was observed for ERG_high cases (OR = 0.29 (95%CI, 0.10-0.8)). Enrichment pathway analysis identified metabolic-related pathways, such as the renin-angiotensin system and angiotensin maturation system, the linoleic acid metabolism, and polyamines metabolism in these ERG groups.

CONCLUSIONS

ERG_low tumor cases were associated with poor BCR-free survival in our Hispanic/Latino patients, with metabolism-related pathways altered in the BCR progression.

IMPACT

Our findings suggest the need to dissect the role of diet, metabolism, and lifestyle as risk factors for more aggressive PCa subtypes.

Determination of ERG(+), EZH2, NKX3.1, and SPINK-1 subtypes to evaluate their association with clonal origin and disease progression in multifocal prostate cancer

BACKGROUND

The prognostic relevance of prostate cancer (PCa) molecular subtypes remains controversial, given the presence of multiple foci with the possibility of different subtypes in the same patient.

AIM

To determine the clonal origin of heterogeneity in PCa and its association with disease progression, SPOP, ERG(+), EZH2, NKX3.1, and SPINK-1 subtypes were analyzed.

METHODS

A total of 103 samples from 20 PCa patients were analyzed; foci of adjacent non-tumor prostate tissue, HGPIN, GL3, GL4, GL5, and LN were examined to determine the presence of the TMPRSS2-ERG fusion and ERG, EZH2, NKX3.1, and SPINK-1 expression levels, using RT-PCR. Mutations in exons 6 and 7 of the SPOP gene were determined by sequencing. The presence of subtypes and molecular patterns were identified by combining all subtypes analyzed. To establish the clonal origin of multifocal PCa, molecular concordance between different foci of the same patient was determined. Association of these subtypes with histopathological groups and time to biochemical recurrence (BCR) was assessed.

RESULTS

No mutation was found in SPOP in any sample. The ERG(+) subtype was the most frequent. The molecular pattern containing all four PCa subtypes was only detected in 3 samples (4%), all LN, but it was the most frequent (40%) in patients. Molecular discordance was the predominant status (55%) when all analyzed molecular characteristics were considered. It was possible to find all subtypes, starting as a preneoplastic lesion, and all but one LN molecular subtype were ERG(+) and NKX3.1 subtypes. Only the expression of the NKX3.1 gene was significantly different among the histopathological groups. No association was found between BCR time in patients and molecular subtypes or molecular concordance or between clinicopathological characteristics and molecular subtypes of ERG, EZH2, and SPINK-1.

CONCLUSION

The predominance of molecular discordance in prostatic foci per patient, which reflects the multifocal origin of PCa foci, highlights the importance of analyzing multiple samples to establish the prognostic and therapeutic relevance of molecular subtypes in a patient. All the subtypes analyzed here are of early onset, starting from preneoplastic lesions. NKX3.1 gene expression is the only molecular characteristic that shows a progression pattern by sample.

KRAS Promoter Methylation Status and miR-18a-3p and miR-143 Expression in Patients With Wild-type KRAS Gene in Colorectal Cancer

BACKGROUND/AIM

Although some mutations of KRAS proto-oncogene, GTPase (KRAS) have been associated with the prognosis and therapeutic management of colorectal cancer (CRC), the epigenetic mechanisms (DNA methylation and microRNA expression) that regulate wild-type KRAS expression in patients with CRC are poorly known. The aim of this study was to establish whether there is a relationship between the expression of the wild-type KRAS gene, the methylation status of its distal promoter, and miR-143 and miR-18a-3p levels in samples of sporadic CRC.

PATIENTS AND METHODS

A total of 51 cases of sporadic CRC with wild-type KRAS were analyzed. The expression levels of KRAS mRNA, miR-18a-3p, miR-143, and KRAS protein, as well as methylation in the distal promoter of the KRAS gene were evaluated.

RESULTS

In the analyzed cases, KRAS mRNA expression was detected in 51.1%; wild-type KRAS protein was found in the membrane in 31.4% and in the cytoplasm in 98% of cases. An inverse relationship of marginal significance was observed between miR-18a-3p and KRAS protein expression in the cytoplasm (odds ratio=0.14, 95% confidence interval=0.012-1.092; p=0.08). The methylation status of the distal promoter of KRAS at four CpG islands was analyzed in 30 cases (58.8%): partial methylation of the four CpG islands evaluated was observed in two cases (6.7%). In these cases, KRAS protein expression was not evidenced at the membrane level; miR-18a-3p expression was not detected either but high expression of miR-143 was observed.

CONCLUSION

No association was found between the expression levels of KRAS mRNA, miR-18a-3p, miR-143 and methylation status. Methylation status was detected with low frequency, thus being the first report of methylation in wild-type KRAS.

Abstract PO-136: Major signaling pathways associated with biochemical recurrence in Hispanic/Latino patients with prostate cancer

Purpose. A high number of diagnosed prostate cancer (PCa) tumors are indolent and will never become aggressive during a patient's lifetime, however, about 20%-40% will experience post-operative disease relapse with biochemical recurrence (BCR), and a fraction of these will progress towards metastatic disease, which is the leading cause of PCa death. Reliable biomarkers helping in management decision-making and avoiding resistant PCa are still needed. We aimed to identify differentially expressed genes (DEGs) associated with BCR in localized PCa and to explore their involvement in signaling pathways contributing to the progression of PCa in Hispanic/Latino patients. Methods. A total of 117 Hispanic/Latino cases with localized PCa were included. RNA was extracted from FFPE tissues of radical prostatectomy (RP), RNA-seq was performed in 75 cases and used to identify DEGs between BCR positive (BCR) and BCR negative (non-BCR) cases. Signaling pathway analysis was done in MetaCore and DAVID database. DEGs with a p-value &lt; 0.1 were used for enrichment analysis. Results. We identified 21 DEGs between BCR and non-BCR cases, three upregulated and 19 downregulated. From the enriched pathway maps found through MetaCore, the most remarkable pathways related with BCR included metabolism of androgen hormones; differentiation, self-renewal and maintenance of stem cells; mechanisms operating in type 2 diabetes (T2DM) and the cooperative action by pioglitazone and rosiglitazone with metformin; and metabolism of triacylglycerol. In line with these findings, results from DAVID also found Diabetes mellitus as one of the keywords, with downregulation of adiponectin (ADIPOQ) and MCF2L2 as the main genes related to this pathway. Other studies have shown that, regardless of BMI, individuals with T2DM have lower plasma adiponectin levels, which, in turn, are associated with pathophysiological conditions such as obesity, metabolic syndrome and insulin resistance. In our study, BMI was not associated with BCR, however, other complementary measurements related to increased abdominal fat (e.g., waist circumference or waist-to-hip ratio), and with recent evidence of strong association with aggressive PCa, were not assessed by us. Additional pathways associated with BCR progression were those related to biosynthesis and metabolism of androgens, being AKR1C the main gene involved. This gene participates in alternative pathways of the biosynthesis of androgens; for example, downregulated AKR1C leads to the synthesis of dihydrotestosterone and circumvents testosterone as a precursor. Conclusions. Enrichment analyses suggest that pathways related to T2DM and metabolism of androgens are main drivers of BCR in Hispanic/Latino PCa patients, mainly through the downregulation of ADIPOQ and AKR1C. Our findings confirm recent discoveries in the molecular understanding of PCa progression, but more studies analyzing abdominal fat measures in independent and larger cohorts could lead as to more precise conclusions, as well as to identify potential biomarkers and therapeutic targets.

Citation Format: Natalia L. Acosta-Vega, Rodolfo Varela, Jorge Andrés Mesa, Jone Garay, Melody C. Baddoo, Alberto Gómez-Gutiérrez, Silvia J. Serrano-Gómez, Martha Lucía Serrano, Jovanny Zabaleta, Alba L. Combita, María Carolina Sanabria-Salas. Major signaling pathways associated with biochemical recurrence in Hispanic/Latino patients with prostate cancer [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-136.

SARS-CoV-2 host tropism: An in silico analysis of the main cellular factors

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The role in host selectivity of ACE2, Tmprss2 and GPR78 in SARS-CoV-2 was explored.

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Differences in the SARS-CoV-2 RBD binding mode with ACE2 of secondary hosts could be associated with host permissiveness.

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Nafamostat could be considered a good inhibitor of mammalian hosts TMPRSS2 proteins.

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In silico studies confirm that the spike protein could interact with GRP78 in studied mammalian hosts.

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TMPRSS2 and GRP78 do not seem to play a role in host selectivity.

Recent reports have shown that small and big felines could be infected by SARS-CoV-2, while other animals, like swines and mice, are apparently not susceptible to this infection. These findings raise the question of the role of cell factors associated with early stages of the viral infection in host selectivity. The cellular receptor for SARS-CoV-2 is the Angiotensin Converting Enzyme (ACE2). Transmembrane protease serine 2 (TMPRSS2) has been shown to prime the viral spike for its interaction with its receptor. GRP78 has also been proposed as a possible co-receptor. In this study, we used several bioinformatics approaches to bring clues in the interaction of ACE2, TMPRSS2, and GRP78 with SARS-CoV-2. We selected several mammalian hosts that could play a key role in viral spread by acting as secondary hosts (cats, dogs, pigs, mice, and ferrets) and evaluated their predicted permissiveness by in silico analysis. Results showed that ionic pairs (salt bridges, N–O pair, and long-range interactions) produced between ACE2 and the viral spike has an essential function in the host interaction. On the other hand, TMPRSS2 and GRP78 are proteins with high homology in all the evaluated hosts. Thus, these proteins do not seem to play a role in host selectivity, suggesting that other factors may play a role in the non-permissivity in some of these hosts. These proteins represent however interesting cell targets that could be explored in order to control the virus replication in humans and in the intermediary hosts.

Circulating miR-141-3p, miR-143-3p and miR-200c-3p are differentially expressed in colorectal cancer and advanced adenomas

Colorectal cancer (CRC) is one of the prominent causes of cancer related deaths because, in part, there is not an early, non-invasive, effective detection strategy. Circulating microRNAs (miRNAs) have been proposed as potential non-invasive biomarkers for CRC. In this study, we evaluated the miRNA profile in sixteen CRC tissues by Next-Generation-Sequencing and compared the circulating expression levels of 22 miRNAs among 45 CRC, 14 hyperplastic polyps, 11 advanced adenoma patients and 45 control subjects, by reverse transcription-quantitative PCR, to search for miRNAs which could be potential biomarkers. In total, nine of them represented 70% of total read counts (miR-10a-5p, miR-192-5p, miR-10b-5p, miR-22-3p, miR-26a-5p, miR-148a-3p, miR-181a-5p, miR-92a-3p and miR-143-5p). In silico analysis found eight candidates to mature miRNAs. With respect to circulating miRNA, we found higher serum expression levels of miR-143-3p, miR-141-3p and miR-200c-3p in the CRC and adenoma groups compared with controls (P<0.002), and we also found significant higher levels of miR-141-3p and miR-200c-3p in serum of adenoma patients compared with the CRC group. In conclusion, the measurement of miRNAs in the blood could complement current screening methods for CRC and might provide new insights into mechanisms of tumorigenesis. miR-143-3p, miR-141-3p and miR-200c-3p could be interesting miRNAs to study as potential biomarkers for CRC.

Identification of three new mutations in the RB1 gene in patients with sporadic retinoblastoma in Colombia

INTRODUCTION

Retinoblastoma is a childhood cancer of the retina originated by altered or null retinoblastoma protein (pRb) expression. Genetic alterations in both RB1 alleles in the retinal cells are required for the development of retinoblastoma. In the sporadic form, non-hereditary RB1 gene mutations take place in a single retinoblast cell, and are therefore only present in tumor DNA (somatic mutations). Sporadic retinoblastoma is primarily unilateral, lacks family history and has no risk of transmission to descendants. Genetic tests for detection of RB1 mutation has improved the identification of carriers and facilitated accurate genetic counseling.

OBJECTIVE

To identify mutations in the RB1 gene in Colombian patients with sporadic retinoblastoma by PCR-SSCP followed by sequence.

MATERIALS AND METHODS

Four patients with sporadic retinoblastoma were analyzed by PCR-SSCP, followed by DNA sequencing to identify variations in the RB1 gene.

RESULTS

We identified five variations in RB1 gene: three new mutations (one germline and two somatic mutations), one new polymorphism and one already reported somatic mutation. Four mutations were found in three patients with unilateral retinoblastoma and one mutation was found in a patient with bilateral retinoblastoma. One of these was a germline mutation in a sporadic unilateral retinoblastoma that was not present in the parents or three siblings analyzed.

CONCLUSIONS

Our results emphasize the importance of identifying mutations for genetic counseling and clinical management of sporadic retinoblastoma patients. Description of a new RB1 gene variant is interesting since there have been a small number of polymorphisms reported for this gene.

Altered HLA class I and HLA-G expression is associated with IL-10 expression in patients with cervical cancer

Although high-risk human papillomaviruses (HPVs) are an important risk factor in the etiopathogenesis of cervical cancer, increasing evidence suggests that the ability to avoid immune surveillance seems to be linked to the transforming potential of HPV and a rapid progression to cancer. In other cancer models, IL-10 contributes to impair anti-tumor immune response either by downregulating human leukocyte antigen Class I (HLA-I) expression or by increasing HLA-G expression. To comprehend how these alterations could contribute to evasion of immune surveillance in cervical cancer, we analyzed HLA-I, HLA-G and IL-10 expressions by immunohistochemistry in 63 biopsies from patients with cervical intraepithelial neoplasia III (CIN-III) and cervical cancer. Immunohistochemistry showed absent or weak HLA-I expression in 50/59 cases. In these cases, a high percentage had loss of heterozygosis. IL-10 and HLA-G expression were observed in 46.6 and 27.6% of cases, respectively. Concurrent upregulation of IL-10 was found in 87.5% of HLA-G positive cases (p = 0.000). Similarly, a significant association between IL-10 expression and HLA-I downregulation was found (p = 0.028). Finally, we observed higher HLA-G expression in patients with HLA-I downregulation than in those with normal HLA-I expression (p = 0.004). Our results suggest that, in cervical cancer, the IL-10 expression may induce an immunosuppressive environment by upregulating HLA-G expression and downregulating HLA class I expression.

Setting up an emergency stock for metabolic diseases

INTRODUCTION

Therapeutic management of inborn errors of metabolism (IEMs) is complicated. The drugs involved are classified as orphan, and their supply depends on whether they are orphan medicines, investigational drugs, or need to be prepared as a compounded formula.

MATERIALS AND METHODS

We analyzed emergency criteria, availability, and permanent location of metabolic drugs within the hospital. Information on therapeutic usage, administration, and dosage was also recorded.

RESULTS

A stock for treating IEMs should include chelating agents, drugs to treat deficiencies, enzyme supplements, and other specific treatments. Hyperammonemia was considered to be life-threatening; therefore, an emergency supply of drugs to treat this condition should be kept permanently in the hospitalization unit.

CONCLUSIONS

Emergency drug stocks are highly recommended in tertiary hospitals in order to improve care for patients susceptible to IEM.

[Intravenous remifentanyl for labor analgesia]

BACKGROUND

Intravenous remifentanil may be the preferred analgesic when regional techniques are contraindicated.

OBJECTIVE

To perform a systematic review on the use of remifentanil for analgesia in labor.

METHODS

We searched MEDLINE (January 1995-August 2007) for studies on obstetric analgesia with remifentanil.

RESULTS

We found 32 references representing the use of remifentanil in 257 women in labor. In most cases, patients reported relief of pain and a high level of satisfaction, with no severe side effects in mothers or neonates. When compared with meperidine and nitrous oxide in clinical trials, remifentanil provided better analgesia with fewer adverse effects.

CONCLUSION

Analgesia with intravenous remifentanil is more effective and safer than other alternatives to regional analgesic techniques in obstetrics. Nevertheless, the optimum system for infusing the drug must b e established and further studies of maternal and fetal safety should be carried out.

Cutaneous metastases of hepatocellular carcinoma

Cutaneous metastases are an unusual finding that may present as the first sign of an internal neoplasia. A case of cutaneous metastases of hepatocellular carcinoma, which may often involve other organs but very rarely metastases to the skin, is reported.

Serum levels of insulin-like growth factor-I and -II and insulin-like growth factor binding protein 3 in women with squamous intraepithelial lesions and cervical cancer

INTRODUCTION

Pap smear has limitations as a screening test for cervical cancer. A marker that allows the identification of women who are at risk of developing cervical cancer would be useful for its prevention. A growing number of studies have demonstrated an association between insulin-like growth factors (IGF) serum levels and increased risk for various cancers. Objective. To assess whether circulating IGF-I, IGF-II, or IGF binding protein 3 (IGFBP-3) were associated with cervical cancer and low-grade and high-grade squamous intraepithelial lesions (LSIL and HSIL).

MATERIALS AND METHODS

Serum levels of IGF-I, IGF-II and IGFBP-3 were measured by ELISA. Three groups of cases were analyzed: LSIL (n = 37), HSIL (n = 57), and cervical cancer (n = 41). For each case, two controls, matched by age, were included. Control subjects were women with normal, HPV-DNA-negative Pap smear.

RESULTS

Significantly lower values of IGF-I (83.9 ng/ml versus 126.6 ng/ml, p < 0.001) and IGF-I:IGFBP-3 molar ratio (0.094 versus 0.137, p < 0.001) were observed among cancer cases, as compared to their control group. Women in the highest quartile of IGF-I and IGF-I:IGFBP-3 molar ratio were at an 80% (OR = 0.2, 95% CI [0.06-0.61]) and a 77% (OR = 0.23, 95% CI [0.07-0.73]) lower risk of cervical cancer, respectively, compared with women in the corresponding reference category.

CONCLUSIONS

These data suggest that low values of IGF-I and IGF-I:IGFBP-3 molar ratio may be associated with cervical cancer.

Systematic genetic study of Alzheimer disease in Latin America: mutation frequencies of the amyloid beta precursor protein and presenilin genes in Colombia

Nearly all mutations in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid beta precursor protein (APP) genes lead to early-onset Alzheimer disease (EOAD, onset age at or before 65 years). In order to assess the genetic contribution of these genes in a series of Colombian AD cases, we performed a systematic mutation analysis in 11 autosomal dominant, 23 familial, and 42 sporadic AD patients (34% with age of onset < or = 65 years). No APP missense mutations were identified. In three autosomal dominant cases (27.2%), two different PSEN1 missense mutations were identified. Both PSEN1 mutations are missense mutations that occurred in early-onset autosomal AD cases: an I143T mutation in one case (onset age 30 years) and an E280A mutation in two other cases (onset ages 35 and 42 years). In addition, a novel PSEN1 V94M mutation was present in one early-onset AD case without known family history (onset age 53 years) and absent in 53 controls. The E318G polymorphism was present in five AD cases and absent in controls. In PSEN2, two different silent mutations were detected, including one not reported elsewhere (P129). The majority of the Colombian AD cases, predominantly late-onset, were negative for PSEN and APP mutations.

A comparison of 0.0625% bupivacaine with fentanyl and 0.1% ropivacaine with fentanyl for continuous epidural labor analgesia

We compared the analgesic efficacy and the degree of motor block achieved with epidural infusion of 0.0625% bupivacaine (Group B) versus 0.1% ropivacaine (Group R), both with 0.0002% fentanyl (2 microg/mL) in laboring patients. A prospective, double-blinded study was performed in 98 ASA physical status I-II parturients who were divided randomly into two groups to receive either bupivacaine or ropivacaine after catheter location had been tested with an initial bolus of lidocaine and fentanyl. The infusion rate was 15 mL/h in every case. When pain was perceived, 5-mL boluses of the assigned epidural analgesic were administered every 10 min until analgesia was achieved. We recorded pain intensity, level of sensory block, degree of motor block, hemodynamic variables, secondary effects, mode of delivery, neonatal outcome, and patient satisfaction. There were no statistically significant differences in any of the factors analyzed. Highly effective analgesia was achieved in both groups with a small incidence of motor block. These findings suggest that bupivacaine may be more potent than ropivacaine.

IMPLICATIONS

We compared different concentrations of epidural bupivacaine and ropivacaine thought to be equipotent. Both solutions were equally efficient in providing highly effective epidural analgesia for labor with minimal motor block. These findings suggest that bupivacaine may be more potent than ropivacaine.

APOE epsilon4 and Alzheimer's disease: positive association in a Colombian clinical series and review of the Latin-American studies

OBJECTIVE

As the strength of the association between the APOE epsilon4 allele and Alzheimer's disease (AD) varies across ethnic groups, we studied if there was such an association in Colombian patients.

METHOD

We performed apolipoprotein E (APOE) genotyping in a clinical sample of 83 unrelated AD patients, predominantly late-onset (>65 yrs) including familial ( n =30) and sporadic AD cases (n= 53) diagnosed according to NINCDS-ADRDA criteria and assessed by a multi-disciplinary team. Control subjects (n = 44) had no significant cognitive impairment by medical interview and neuro-psychological testing.

RESULTS

We found a high association (OR= 5.1 95%CI 1.9 -13.6) between APOE epsilon4 and AD, in this series with predominantly late-onset cases with familial aggregation in 24 cases (28.9%). A significant negative association was found between epsilon2 and AD (OR= 0.2 95% CI 0.05-0.75).

CONCLUSION

Further population-based surveys in Colombia are warranted to precise a possible dose effect of APOE epsilon4.

Coordination chemistry of co(II)-bleomycin: its investigation through NMR and molecular dynamics

Previous studies on the coordination chemistry of Co-bleomycin have suggested the secondary amine in beta-aminoalanine, the N5 and N1 nitrogens in the pyrimidine and imidazole rings, respectively, and the amide nitrogen in beta-hydroxyhistidine as equatorial ligands to the cobalt ion. The primary amine in beta-aminoalanine and the carbamoyl group of the mannose have been proposed alternatively as possible axial ligands. The first coordination sphere of Co(II) in Co(II)BLM has been investigated in the present study through the use of NMR and molecular dynamics calculations. The data collected from the NMR experiments are in agreement with the equatorial ligands previously proposed, and also support the participation of the primary amine as an axial ligand. The paramagnetic shifts of the gulose and mannose protons could suggest the latter as a second axial ligand. This possibility was investigated by way of molecular dynamics, with distance restraints derived from the relaxation times measured through NMR. The molecular dynamics results indicate that the most favorable structure is six-coordinate, with the primary amine and either the carbamoyl oxygen or a solvent molecule occupying the axial sites. The analysis of the structures previously derived for HOO-Co(III)-bleomycin and HOO-Co(III)-pepleomycin led us to propose the six-coordinate structure with only endogenous ligands, as the one held in solution by the Co(II) derivative of bleomycin.

[Extracorporeal respiratory assistance (ECRA): initial experiences in Spain]

The attendance respiratory extracorporeal (AREC) is an oxygenation form for membrane extracorporeal with flow tidal and veno-venous cannula described by Chevalier et al. in 1990. We present our clinical experience so much with AREC in system veno-venous flow tidal as veno-arterial. From october of 1997 until the present time we have treated three patients by means AREC, in two patients with veno-venous system and in one veno-arterial. In all the cases bomb Collin-Cardio has been used with bladder for flow tidal and membrane of oxygenation of 0.8 m2, being inserted a system of alternative clamp of the branches of the circuit. The system AREC has been used in two patients with congenial diaphragmatic hernia, right in a case and left in the other one. The gestational age was of 38 and 36 weeks with a weight of 3,200 and 2,900 grams. Both patients were remitted from other centers by failure of the conventional treatment. In both cases the indication of AREC was the sharp deterioration of the general state with failure of the conservative treatment, being the previous oxygenation index of 109 and 112. The third patient precised veno-arterial AREC for ventricular failure during the correction of the congenital heart disease, this patient was 5 month old and the weight was 5,000 grams. The duration of AREC in the cases of congenital diaphragmatic hernia was of 14 and 10 days. In a patient the diaphragmatic hernia was corrected at the 55 hours of being in AREC. In the second case the hernia had been surgical corrected in another center. The exit of AREC in both cases carries out after a discreet improvement of the lung function. Both patients died at the 24 and 48 hours of the decannulation for cerebral hemorrhage and respiratory failure. The third patient stayed stable in veno-arterial AREC during 4 days, with hemodynamic support of 130 ml/kg/min, retiring the support to present absence of cerebral activity.

CONCLUSIONS

With the derived limitations of the extreme severity of the treated cases and the current phase of beginning of the AREC team, we think that it is a useful and available technique in our country, for the handling of patient with cardiorespiratory failure while waiting for improvement of their base pathology.

[Wallenberg syndrome in childhood secondary to the striking by lightening]

Wallenberg's Syndrome (WS) is exceptional in childhood. We present a case of a 10 year-old girl with a WS caused by an embolism in the right lateral portion of the medulla secondary to an electrofulguration, but with an unusual progressive outcome, developing clinical signs of medial medullar injury, leading even into a respiratory failure 30 days after admittance. She only became stable after surgical lesion decompression. There was no evidence of vascular malformation, finding only a great oedema. The pathology only showed changes compatible with brain infarction. This case makes again clear the superiority of MRI upon CT-scan to diagnose a WS. We think that the unusual progression of the lesion was due to great medullar oedema found on surgery, involving the brain regional flow.

[Peptic ulcer in children]

Gastric and duodenal ulcers diagnosed by endoscopic examination are evaluated. Fasting and after lunch test serum gastrin levels were elevated. Other endoscopic findings were found in 42% of patients. Last histological examination revealed that gastritis and gastroduodenitis may coexist. With endoscopic examination incidence of peptic ulcus has increased in the pediatric age.