Oral quinolones versus intravenous ß-lactam for the treatment of acute focal bacterial nephritis: a retrospective cohort study.

BACKGROUND: Evidence regarding the best antibiotic regimen and the route of administration to treat acute focal bacterial nephritis (AFBN) is scarce. The aim of the present study was to compare the effectiveness of intravenous (IV) ß-lactam antibiotics versus oral quinolones. METHODS: This is a retrospective single centre study of patients diagnosed with AFBN between January 2017 and December 2018 in Hospital Universitari Vall d'Hebron, Barcelona (Spain). Patients were identified from the diagnostic codifications database. Patients treated with oral quinolones were compared with those treated with IV ß-lactam antibiotics. Therapeutic failure was defined as death, relapse, or evolution to abscess within the first 30 days. RESULTS: A total of 264 patients fulfilled the inclusion criteria. Of those, 103 patients (39%) received oral ciprofloxacin, and 70 (26.5%) IV ß-lactam. The most common isolated microorganism was Escherichia coli (149, 73.8%) followed by Klebsiella pneumoniae (26, 12.9%). Mean duration of treatment was 21.3 days (SD 7.9). There were no statistical differences regarding therapeutic failure between oral quinolones and IV ß-lactam treatment (6.6% vs. 8.7%, p = 0.6). Out of the 66 patients treated with intravenous antibiotics, 4 (6.1%) experienced an episode of phlebitis and 1 patient (1.5%) an episode of catheter-related bacteraemia. CONCLUSIONS: When susceptible, treatment of AFBN with oral quinolones is as effective as IV ß-lactam treatment with fewer adverse events.

Glacier retreat reorganizes river habitats leaving refugia for Alpine invertebrate biodiversity poorly protected.

Alpine river biodiversity around the world is under threat from glacier retreat driven by rapid warming, yet our ability to predict the future distributions of specialist cold-water species is currently limited. Here we link future glacier projections, hydrological routing methods and species distribution models to quantify the changing influence of glaciers on population distributions of 15 alpine river invertebrate species across the entire European Alps, from 2020 to 2100. Glacial influence on rivers is projected to decrease steadily, with river networks expanding into higher elevations at a rate of 1% per decade. Species are projected to undergo upstream distribution shifts where glaciers persist but become functionally extinct where glaciers disappear completely. Several alpine catchments are predicted to offer climate refugia for cold-water specialists. However, present-day protected area networks provide relatively poor coverage of these future refugia, suggesting that alpine conservation strategies must change to accommodate the future effects of global warming.

Molecular analysis in cytological samples obtained by endobronchial or oesophageal ultrasound guided needle aspiration in non-small cell lung cancer.

INTRODUCTION: Cytological samples obtained by endobronchial ultrasound (EBUS) are capital for diagnosis, staging and molecular profile in non-small cell lung carcinoma (NSCLC). OBJECTIVE: To assess the success rate of complete, partial and individual of molecular analysis in samples obtained by EBUS-guided transbronchial needle aspiration (TBNA) and/or by oesophageal ultrasound-guided fine needle aspiration with an echobronchoscope (EUS-B-FNA) in patients with NSCLC. METHODS: Prospective study including 90 patients with non-squamous NSCLC, or non-smoking squamous. Cytological samples were classified into two groups. Group 1: PEN membrane slide and/or cell blocks for the determination of mutations of EGFR, KRAS, ERBB2 and BRAF. Group 2: silane coated slides or cell blocks for rearrangements of ALK, ROS1 and MET amplification. RESULTS: The success rate was 78.6% for 4 molecular alterations (EGFR, KRAS, ALK and ROS1), and 44% for 7 determinations. The individual success rate for EGFR was 97%, KRAS 96.3%, ALK 85%, ROS1 82.3%, ERBB2 71.4%, BRAF 67.7% and MET 81.1%. There were no significant differences (p=0.489) in the number of molecular analyses (1-3 vs. 4) in group 1, depending on the types of samples (cell block vs. PEN membrane slide vs. cell block and PEN membrane slide). CONCLUSIONS: In patients with NSCLC, the cytological material obtained by ultrasound-guided needle aspiration is sufficient for individual and partial molecular analysis in the vast majority of cases. Membrane slides such as cell blocks are valid samples for molecular analysis.

Identification of oestrogen, progesterone receptor and human epidermal growth factor receptor 2 expression in mediastinal metastases of breast cancer obtained by endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND: In breast cancer patients, the expression statuses of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are crucial in the choice of treatment. Receptor expression in metastatic lesions can differ from the primary tumour. The aim of our study was to analyse the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to obtain samples allowing the identification of ER, PR and HER2 expression in patients with mediastinal metastases of breast cancer. PATIENTS AND METHODS: The clinical files of all patients with a final diagnosis of breast cancer mediastinal metastases diagnosed by EBUS-TBNA in our institution were retrospectively analysed. The ability of EBUS-TBNA to obtain samples that allowed hormone receptor and HER2 expression analysis was calculated. RESULTS: Twenty-four patients were included. ER, PR and HER2 assessments could be performed in 22, 20 and 22 patients, respectively. In 20 of the 24 patients it was possible to investigate all three types of receptor expression. In the remaining four cases, where ER, PR or HER2 expression tests could not be performed, it was due to a lack of tissue. In cases with adequate results for EBUS-TBNA and the primary tumour agreement was greater for ER (16/19) and HER2 (12/14) than PR (8/17). Based on receptor status, there was a change in the choice of treatment for five patients. CONCLUSION: In patients with breast cancer mediastinal metastases, ER, PR and HER2 expression can be assessed in samples obtained by EBUS-TBNA whenever a sufficient tissue sample is collected.

Stem cell-like transcriptional reprogramming mediates metastatic resistance to mTOR inhibition.

Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.

Classical markers like ER and ki-67, but also survivin and pERK, could be involved in the pathological response to gemcitabine, adriamycin and paclitaxel (GAT) in locally advanced breast cancer patients: results from the GEICAM/2002-01 phase II study

INTRODUCTION: The identification and validation of biomarkers of chemotherapy sensitivity is critical in order to individualise therapy in breast cancer. We evaluated pathological complete response (pCR) to GAT, and its correlation with tumour biomarkers before and after neoadjuvant chemotherapy. MATERIALS AND METHODS: Stage III (and stage II with T≥5 cm) breast cancer patients were included. Treatment consisted of adriamycin (40 mg/m(2)) day 1, and paclitaxel (150 mg/ m(2)) followed by gemcitabine (2000 mg/m(2)) day 2, every 14 days for six cycles. Tissue from pre-treatment biopsy and surgery was evaluated for biologic markers by immunohistochemistry. Two XPD single nucleotide polymorphisms (SNP) were also analysed. RESULTS: Forty-six patients entered the trial. Median age was 49.5 years (range 31-72); 25 patients (54%) were pre-menopausal; 12 (26%) were ER-PgR-negative; pCR was observed in 17% (95% CI: 6.4-28.4) of patients. Significant differences in marker expression (mean±SD) in correlation to pathological response were only found in Ki- 67. After treatment, tumours showed lower Ki-67-, surviving- and pERK-positive cells. No correlation between XPD polymorphisms and pCR was found. The overall response rate was 89% (95% CI: 80.1-98.1). Fifteen patients (33%) underwent breast-conserving surgery. The most frequent grade 3 or 4 toxicities were neutropenia (with one febrile neutropenia) and asthenia. CONCLUSION: These results show an effective regimen with acceptable tolerability. Our data suggest that not only classical markers (ER, Ki-67), but also survivin and pERK could be involved in the response to GAT, which may contribute to therapy individualisation in future study designs (AU)

Representativeness of nodal sampling with endobronchial ultrasonography in non-small-cell lung cancer staging.

The objective of our study was to determine the procedure-related requirements of mediastinal node sampling with endobronchial ultrasonography with real-time transbronchial needle aspiration (EBUS-TBNA) that would provide negative predictive value (NPV) for the identification of stage III disease in non-small-cell lung cancer (NSCLC) high enough to consider the technique equivalent to cervical mediastinoscopy. Representative EBUS-TBNA was defined as a sampling procedure obtaining satisfactory samples from normal nodes in regions 4R, 4L and 7 or diagnosing malignancy in mediastinal nodes. NPV was estimated using the results of postsurgical staging in patients who underwent surgery as a reference. Two-hundred ninety-six patients staged with EBUS-TBNA were included. Representative samples from regions 4R, 4L and 7 showing nonmalignant cytology were obtained from 98 patients (33.1%) and EBUS-TBNA detected N2/N3 disease in 150 (50.7%). Accordingly, an EBUS-TBNA procedure accomplishing the representativeness criteria required for sampling was attained in 248 of the participating patients (83.8%). The NPV of the procedure in this setting was 93.6%, with false-negative results only found in 5 patients, four of them with nodal metastasis out of the reach of EBUS-TBNA (regions 5, 8 and 9). In conclusion, representative sampling of regions 4R, 4L and 7 is achieved in more than 80% of patients staged using EBUS-TBNA, and in the procedures that attain this requirement a NPV >90% for mediastinal malignancy is reached, a figure equivalent to cervical mediastinoscopy.

Monitorización de la respuesta a la terapia neoadyuvante en el carcinoma de mama localmente avanzado mediante métodos de imagen / No disponible

Objetivo: Establecer la validez diagnóstica de la mamografía, de la resonancia magnética y de la gammagrafía 99mTc-sestamibi en la valoración de la respuesta terapéutica de pacientes diagnosticadas de carcinoma de mama localmente avanzado. Pacientes y métodos: Estudio prospectivo observacional aprobado por el Comité Ético de nuestra institución en el que se han incluido 75 pacientes diagnosticadas de carcinoma de mama localmente avanzado por core biopsia (edad media: 52 años, rango: 26-80 años). Las pacientes fueron valoradas clínicamente, por mamografía, resonancia magnética y gammagrafía 99mTc-sestamibi antes de iniciar la terapia neoadyuvante y una vez finalizada la misma. Se han administrado regímenes terapéuticos basados en antraciclinas excepto en siete pacientes que recibieron hormonoterapia con inhibidores de la aromatasa. Para la valoración de la respuesta clínica se utilizaron los criterios RECIST y los mismos criterios, adaptados y consensuados, se emplearon para la valoración de la respuesta mediante técnicas de imagen e histología. Resultados: Tras cirugía se constató respuesta histológica, bien sea parcial o completa, en 61 pacientes (81,3%). Se evidenció conformidad entre la respuesta clínica y los hallazgos histológicos en el 80% de los casos, entre mamografía e histología en el 79,7% de casos, y esta fue del 78,9 % para la resonancia magnética y del 86,4% para la gammagrafía. La sensibilidad y especificidad fueron del 64,3 y del 83,8% para la mamografía, del 61,5 y 82,8% para la resonancia magnética, y del 58,3 y 92,6%, para la gammagrafía. Se pudo observar una concordancia del 88,8% entre resonancia y gammagrafía, del 75,7% entre esta y la mamografía y del 77,3 % entre gammagrafía y mamografía. Conclusiones: La resonancia magnética y la gammagrafía 99mTc-sestamibi demuestran su utilidad en la valoración de la respuesta tras la terapia neoadyuvante, si bien persiste la dificultad en la valoración de focos microscópicos de tumor o del componente in situ, y por tanto, en la definición de respuesta completa(AU)

Aim: To establish diagnostic validity of mammography, mammary magnetic resonance and 99mTc-sestamibi scintimammography to assess response to neoadjuvant therapy in patients with locally advanced breast cancer. Patients and methods: A prospective observational study was approved at our institution which included 75 women with core biopsy diagnostic of locally advanced breast cancer (mean age: 52 y, range 26-80 y). All patients had clinical, mammography, mammary magnetic resonance and 99mTc-sestamibi scintimammography assessment before and after receiving neoadjuvant therapy. Primary chemotherapy based on anthracyclines was administered except in seven patients who received endocrine therapy with aromatase inhibitors. RECIST criteria were considered for clinical response assessment, and the same criteria were adapted for imaging methods and pathologic response. Results: After surgery, 61 patients (81,3%) showed histologic response (complete or partial). Clinical assessment of tumour response was in concordance with histologic study in 80% of patients. Mammography, magnetic resonance and scintimammography agreed with pathology in 79,7, 78,9 and 86,4% of patients, respectively. Based on histologic response, sensitivity and specificity were 64,3 and 83,8% for mammography, 61,5 and 82,8% for magnetic resonance, and 58,3 and 92,6% for scintimammography, respectively. Agreement between magnetic resonance and scintimammography was 88,8%, between magnetic resonance and mammography 75,7%, and 77,3% between scintimammography and mammography. Conclusion: Magnetic resonance and scintimammography should be added to the diagnostic arsenal since they have shown more reliability than conventional methods for predicting histopathologic response to neoadjuvant therapy. Nevertheless, tumour size is critical for the detection of residual small lesions, usually microscopic and DCIS foci, or in others words, there is a limitation to define complete response(AU)

Breast Cancer OncoGuia: surgical pathology report guidelines

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Endobronchial ultrasound-guided transbronchial needle aspiration for identifying EGFR mutations.

The presence of somatic mutations of the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene in patients with advanced nonsmall cell lung cancer (NSCLC) correlates with a good response to tyrosine kinase inhibitors. The usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the detection of EGFR mutations in cells recovered from malignant mediastinal nodes in patients with NSCLC was assessed. All patients with lung adenocarcinoma or unspecified NSCLC referred for staging with EBUS-TBNA were included. Nodes with a short-axis diameter of >5 mm were sampled, and genomic DNA from metastatic tumour cells was obtained for analysis of exons 19 and 21. The impact of sampling on management was assessed. EGFR gene analysis of the EBUS-TBNA sample was feasible in 26 (72.2%) out of the 36 patients with lymph node metastasis. Somatic mutations of the EGFR gene were detected in tissue obtained through EBUS-TBNA in two (10%) out of 20 patients with metastasic lung adenocarcinoma. Malignant tissue samples obtained by EBUS-TBNA from patients with nodal metastasis of NSCLC are suitable for the detection of EGFR mutations in most cases, and this technique demonstrates mutated neoplastic cells in a tenth of patients with adenocarcinoma.

Doxorubicin and cyclophosphamide followed by weekly docetaxel as neoadjuvant treatment of early breast cancer: analysis of biological markers in a GEICAM phase II study.

INTRODUCTION: To evaluate the sequential administration of doxorubicin (A) and cyclophosphamide (C) followed by weekly docetaxel in women with stage II to IIIA breast cancer. PATIENTS AND METHODS: Patients received 60 mg/m(2) of A and 600 mg/m(2) of C every three weeks for four cycles followed by 12 infusions of weekly docetaxel at a dose of 36 mg/m(2) and with a 2-week resting period. RESULTS: Sixty-three women were included. On an intention-to- treat basis, clinical response rate was 90% (95% CI: 83-98), with 46% complete responses. Breast-conserving surgery could be performed in 43 patients (68%). Complete pathological responses in the breast were confirmed in 17% of patients. No correlations between levels of expression of topoisomerase II alpha, survivin or p27 and the pathological response were detected. The study treatment was generally well tolerated. CONCLUSION: Neoadjuvant AC followed by weekly docetaxel is a feasible regimen for patients with early-stage breast cancer.

Doxorubicin and cyclophosphamide followed by weekly docetaxel as neoadjuvant treatment of early breast cancer: analysis of biological markers in a GEICAM phase II study

INTRODUCTION: To evaluate the sequential administration of doxorubicin (A) and cyclophosphamide (C) followed by weekly docetaxel in women with stage II to IIIA breast cancer. PATIENTS AND METHODS: Patients received 60 mg/m(2) of A and 600 mg/m(2) of C every three weeks for four cycles followed by 12 infusions of weekly docetaxel at a dose of 36 mg/m(2) and with a 2-week resting period. RESULTS: Sixty-three women were included. On an intention-to- treat basis, clinical response rate was 90% (95% CI: 83-98), with 46% complete responses. Breast-conserving surgery could be performed in 43 patients (68%). Complete pathological responses in the breast were confirmed in 17% of patients. No correlations between levels of expression of topoisomerase II alpha, survivin or p27 and the pathological response were detected. The study treatment was generally well tolerated. CONCLUSION: Neoadjuvant AC followed by weekly docetaxel is a feasible regimen for patients with early-stage breast cancer (AU)

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Ablación del cáncer de mama mediante técnica de radiofrecuencia. Experiencia inicial / No disponible

Objetivo: Valorar la efectividad de la ablación por radiofrecuencia(ARF) en el tratamiento local del cáncer de mama enestadios iniciales.Pacientes y métodos: La ARF guiada por imagen ecográficase practicó en 4 pacientes (de los 30 inicialmente previstoscomo objeto de reclutamiento) en quirófano bajo anestesia general.La resección del lecho tumoral se llevó a cabo 2-3 semanasdespués. La valoración pre- y post-ARF se efectuó medianteimagen ecográfica, mamográfica y resonanciamagnética (RM).Resultados: El análisis anatomo-patológico determinó presenciade tejido tumoral en todos los casos, mientras que laRM informó tejido viable en 1 de los 3 casos en que se efectuó.Estos resultados no permitieron continuar el reclutamientode pacientes.Discusión: La radiofrecuencia es la técnica actualmentemás atractiva para la realización de la ablación no quirúrgicaen el tratamiento primario del cáncer de mama. El presentetrabajo pretende aportar una visión real, basada tanto en laexperiencia propia como en la literatura publicada. Con estaspremisas discutimos nuestros resultados, desalentadores aunquepreliminares, así como la bondad de la técnica en cuantoa eficacia de ablación tumoral y la posibilidad futura de sustituirla exéresis quirúrgica de la tumoración, principal motivaciónde los estudios actuales(AU)

Objective: To evaluate the efficacy of radiofrequency ablation(RFA) therapy for breast cancer.Patients and methods: Only four of the 30 initially scheduledpatients underwent ultrasound-guided RFA under generalanesthesia. Lumpectomy was performed 2-3 weeks after theRFA procedure.Results: Post-RFA MRI scans revealed lesion enhancementin 1 of 3 patients, however residual tumor was confirmedhistopathologically in all four patients. Because of such discouragingresults we decided to stop patient enrollment.Discussion: Nowadays, RFA is the most promising ablationtechnique for primary breast cancer treatment. Based on publishedstudies and on our own experience, an overview ofbreast cancer RFA is presented. We discuss both technicalRFA issues and pros compared with standard surgical treatment(AU)

Evolutionary aspects of population structure for molecular and quantitative traits in the freshwater snail Radix balthica.

Detecting the action of selection in natural populations can be achieved using the QST-FST comparison that relies on the estimation of FST with neutral markers, and QST using quantitative traits potentially under selection. QST higher than FST suggests the action of directional selection and thus potential local adaptation. In this article, we apply the QST-FST comparison to four populations of the hermaphroditic freshwater snail Radix balthica located in a floodplain habitat. In contrast to most studies published so far, we did not detect evidence of directional selection for local optima for any of the traits we measured: QST calculated using three different methods was never higher than FST. A strong inbreeding depression was also detected, indicating that outcrossing is probably predominant over selfing in the studied populations. Our results suggest that in this floodplain habitat, local adaptation of R. balthica populations may be hindered by genetic drift, and possibly altered by uneven gene flow linked to flood frequency.

[Having diabetes without knowing it]. / Tener diabetes y no saberlo. Cribaje de diabetes desconocida en una muestra oportunista de población residente en Cataluña.

As part of the activities on the World Day for Diabetes in 2002, nine professors, one nurse who teaches about diabetes and 126 nursing students at University Schools of Nursing in Barcelona, Lleida, Tarragona, Tortosa and Girona, in collaboration with the Association of Diabetics in Catalonia and with the help of the Advisory Council for Diabetes in Catalonia participated in a diabetes screening campaign on the population residing in Catalonia. This campaign studied the prevalence of type two diabetes in a random sample of the Catalan population. This campaign also proposed to raise the awareness among the general population and among nursing students about the important health consequences diabetes has and to increase investigation and social support measures by nurses related to diabetes. This study checked 4083 persons and discovered 77 cases of altered blood-sugar levels among people who did not know they had diabetes. This finding means that there is a 2.2% prevalence of altered blood-sugar levels in the population who are not diagnosed diabetics. Professors and student participants all gave this experience positive marks and the students' degree of satisfaction was very high.

Tener diabetes y no saberlo / Having diabetes without knowing it

Con motivo del Día Mundial de la Diabetes de 2002, nueve profesoras, una enfermera educadora en diabetes y 126 estudiantes de enfermería de Escuelas Universitarias de Enfermería de Barcelona, Tarragona, Tortosa y Girona, en colaboración con la Asociación de Diabéticos de Cataluña y con el soporte del "Consell Asesor de la Diabetis a Catalunya", participan en una campaña de cribado de diabetes en la población residente en Cataluña. Esta campaña estudia la prevalencia de diabetes tipo 2 en una muetra oportunista de la población catalana. También pretende sensibilizar a la población general y a los estudiantes de enfermería de la importancia sanitaria de esta enfermedad y potentar el rol investigador y social de la enfermera. Se estudian 4.083 personas y se encuentran 77 glucemias alteradas entre la población sin diabetes conocida. Esto supone una prevalencia de glucemias alteradas del 2,2% en la población no diagnosticada de diabetes. Tanto los profesores como los alumnos participantes valoran positivamente esta experiencia y el ni vel de satisfacción de los estudiantes es muy elevado

As part of the activities on the World Day for Diabetes in 2002, nine professors, one nurse who teaches about diabetes and 126 nursing students at University Schools of Nursing in Barcelona, Lleida, Tarragona, Tortosa and Girona, in collaboration with the Association of Diabetics in Catalonia and with the help of the Advisory Council for Diabetes in Catalonia participated in a diabetes screening campaign on the population residing in Catalonia. This campaign studied the prevalence of type two diabetes in a random sample of the Catalan population. This campaign also proposed to raise the awareness among the general population and among nursing students about the important health consequences diabetes has and to increase investigation and social support measures by nurses related to diabetes. This study checked 4083 persons and discovered 77 cases of altered blood-sugar levels among people who did not know they had diabetes. This finding means that there is a 2.2% prevalence of altered blood-sugar levels in the population who are not diagnosed diabetics. Professors and student participants all gave this experience positive marks and the students' degree of satisfaction was very high

Breast hemangioma mimicking carcinoma.

Breast hemangiomas are rare, and usually appear as well-delimited round or oval nodules at mammography. We report a case of a woman with a breast hemangioma, which mammographic features simulated malignancy, and present its pathologic correlation. Hemangiomas are benign vascular tumors that are rarely present in the breast, usually found incidentally on microscopy of biopsy material for other. They are occasionally detected by mammography, presenting as well-delimited round, lobulated nodules, sometimes with calcifications. We present the mammographic findings and pathologic correlation in a case of breast hemangioma with an atypical radiological manifestation, simulating a carcinoma. To our knowledge, this is the first reported case with these radiologic characteristics.

Effect of L-arginine on the course of experimental colitis.

BACKGROUND AND AIMS: L-Arg is the substrate for nitric oxide, and also for L-ornithine which, in turn, is the precursor for the synthesis of collagen and polyamines. By these different metabolic pathways, L-Arg is involved in the mechanisms of inflammation, tissue repair and fibrosis. Thus, the aim of this study was to assess the effect of both different amounts of L-Arg supplementation and L-Arg-free diets upon colonic inflammatory damage and fibrosis in experimental colitis. METHODS: Sprague-Dawley rats with trinitrobenzene sulphonic acid (TNBS)-induced colitis received increasing doses of L-Arg (30, 100, 500 mg/day), or D-Arg (500 mg/day). In a second experiment, two L-Arg-free diets (one supplemented with L-Gly) were compared to a L-Arg diet. Nitrite/nitrate release in the lumen of the colon and colonic damage were evaluated. In the first experiment, tissue collagen levels and colonic mucosal proliferation were also assessed. RESULTS: In the acute phase of colitis, intracolonic nitrite/nitrate levels were significantly higher in the 100 and 500 mg supplemented L-Arg groups than in D-Arg group. However, only rats treated with 500 mg of L-Arg showed moderately higher inflammatory and fibrosis colonic scores than the D-Arg treated rats. There was no significant influence of L-Arg-free diets on the course of TNBS-induced colitis. However, L-Arg diet accelerated weight gain both pre- and post-TNBS. CONCLUSIONS: These results suggest that normal amounts of L-Arg in the diet are not harmful, whereas both absence of L-Arg or supplementation with high doses of this amino acid may be deleterious. In the former this might be due to a decrease of nitrogen retention in injured rats, whereas in the latter it may result from both nitric oxide-mediated tissue damage and collagen deposition.