Regulatory and metabolic adaptations in the nitrogen assimilation of marine picocyanobacteria.

Prochlorococcus and Synechococcus are the two most abundant photosynthetic organisms on Earth, with a strong influence on the biogeochemical carbon and nitrogen cycles. Early reports demonstrated the streamlining of regulatory mechanisms in nitrogen metabolism and the removal of genes not strictly essential. The availability of a large series of genomes, and the utilization of latest generation molecular techniques have allowed elucidating the main mechanisms developed by marine picocyanobacteria to adapt to the environments where they thrive, with a particular interest in the strains inhabiting oligotrophic oceans. Given that nitrogen is often limited in those environments, a series of studies have explored the strategies utilized by Prochlorococcus and Synechococcus to exploit the low concentrations of nitrogen-containing molecules available in large areas of the oceans. These strategies include the reduction in the GC and the cellular protein contents; the utilization of truncated proteins; a reduced average amount of N in the proteome; the development of metabolic mechanisms to perceive and utilize nanomolar nitrate concentrations; and the reduced responsiveness of key molecular regulatory systems such as NtcA to 2-oxoglutarate. These findings are in sharp contrast with the large body of knowledge obtained in freshwater cyanobacteria. We will outline the main discoveries, stressing their relevance to the ecological success of these important microorganisms.

Initial findings in chest X-rays as predictors of worsening lung infection in patients with COVID-19: correlation in 265 patients.

BACKGROUND AND AIMS: We aimed to analyze the relationship between the initial chest X-ray findings in patients with severe acute respiratory syndrome due to infection with SARS-CoV-2 and eventual clinical worsening and to compare three systems of quantifying these findings. MATERIAL AND METHODS: This retrospective study reviewed the clinical and radiological evolution of 265 adult patients with COVID-19 attended at our center between March 2020 and April 2020. We recorded data related to patients' comorbidities, hospital stay, and clinical worsening (admission to the ICU, intubation, and death). We used three scoring systems taking into consideration 6 or 8 lung fields (designated 6A, 6B, and 8) to quantify lung involvement in each patient's initial pathological chest X-ray and to classify its severity as mild, moderate, or severe, and we compared these three systems. We also recorded the presence of alveolar opacities and linear opacities (fundamentally linear atelectasis) in the first chest X-ray with pathologic findings. RESULTS: In the χ2 analysis, moderate or severe involvement in the three classification systems correlated with hospital admission (P = .009 in 6A, P = .001 in 6B, and P = .001 in 8) and with death (P = .02 in 6A, P = .01 in 6B, and P = .006 in 8). In the regression analysis, the most significant associations were 6B with alveolar involvement (OR 2.3; 95%CI 1.1.-4.7; P = .025;) and 8 with alveolar involvement (OR 2.07; 95% CI 1.01.-4.25; P = .046). No differences were observed in the ability of the three systems to predict clinical worsening by classifications of involvement in chest X-rays as moderate or severe. CONCLUSION: Moderate/severe extension in the three chest X-ray scoring systems evaluating the extent of involvement over 6 or 8 lung fields and the finding of alveolar opacities in the first pathologic X-ray correlated with mortality and the rate of hospitalization in the patients studied. No significant difference was found in the predictive ability of the three classification systems proposed.

Indirect genomic predictions for milk yield in crossbred Holstein-Jersey dairy cattle.

The objective of this study was to predict genomic breeding values for milk yield of crossbred dairy cattle under different scenarios using single-step genomic BLUP (ssGBLUP). The data set included 13,880,217 milk yield measurements on 6,830,415 cows. Genotypes of 89,558 Holstein, 40,769 Jersey, and 22,373 Holstein-Jersey crossbred animals were used, of which all Holstein, 9,313 Jersey, and 1,667 crossbred animals had phenotypic records. Genotypes were imputed to 45K SNP markers. The SNP effects were estimated from single-breed evaluations for Jersey (JE), Holstein (HO) and crossbreds (CROSS), and multibreed evaluations including all Jersey and Holstein (JE_HO) or approximately equal proportions of Jersey, Holstein, and crossbred animals (MIX). Indirect predictions (IP) of the validation animals (358 crossbred animals with phenotypes excluded from evaluations) were calculated using the resulting SNP effects. Additionally, breed proportions (BP) of crossbred animals were applied as a weight when IP were estimated based on each pure breed. The predictive ability of IP was calculated as the Pearson correlation between IP and phenotypes of the validation animals adjusted for fixed effects in the model. Regression of adjusted phenotypes on IP was used to assess the inflation of IP. The predictive ability of IP for CROSS, JE, HO, JE_HO, and MIX scenario was 0.50, 0.50, 0.47, 0.50, and 0.46, respectively. Using BP was the least successful, with a predictive ability of 0.32. The inflation of the IP for crossbred animals using CROSS, JE, HO, JE_HO, MIX, and BP scenarios were 1.17, 0.65, 0.55, 0.78, 1.00, and 0.85, respectively. The IP of crossbred animals can be predicted using single-step GBLUP under a scenario that includes purebred genotypes.

[Initial findings in chest X-rays as predictors of worsening lung infection in patients with COVID-19: correlation in 265 patients]. / Hallazgos iniciales en la radiografía de tórax como predictores de empeoramiento en la infección pulmonar por SARS-CoV-2. Correlación en 265 pacientes.

Background and aims: We aimed to analyze the relationship between the initial chest X-ray findings in patients with severe acute respiratory syndrome due to infection with SARS-CoV-2 and eventual clinical worsening and to compare three systems of quantifying these findings. Material and methods: This retrospective study reviewed the clinical and radiological evolution of 265 adult patients with COVID-19 attended at our center between March 2020 and April 2020. We recorded data related to patients' comorbidities, hospital stay, and clinical worsening (admission to the ICU, intubation, and death). We used three scoring systems taking into consideration 6 or 8 lung fields (designated 6 A, 6 B, and 8) to quantify lung involvement in each patient's initial abnormal chest X-ray and to classify its severity as mild, moderate, or severe, and we compared these three systems. We also recorded the presence of alveolar opacities and linear opacities (fundamentally linear atelectasis) in the first chest X-ray with pathologic findings. Results: In the χ2 analysis, moderate or severe involvement in the three classification systems correlated with hospital admission (p = 0.009 in 6 A, p = 0.001 in 6 B, and p = 0.001 in 8) and with death (p = 0.02 in 6 A, p = 0.01 in 6 B, and p = 0.006 in 8). In the regression analysis, the most significant associations were 6 B with alveolar involvement (OR 2.3; 95%CI 1.1.-4.7; p = 0.025;) and 8 with alveolar involvement (OR 2.07; 95% CI 1.01.-4.25; p = 0.046). No differences were observed in the ability of the three systems to predict clinical worsening by classifications of involvement in chest X-rays as moderate or severe. Conclusion: Moderate/severe extension in the three chest X-ray scoring systems evaluating the extent of involvement over 6 or 8 lung fields and the finding of alveolar opacities in the first abnormal X-ray correlated with mortality and the rate of hospitalization in the patients studied. No significant difference was found in the predictive ability of the three classification systems proposed.

Significant differences in access to tests and treatments for multiple myeloma between public and private systems in Latin America. Results of a Latin American survey. GELAMM (Grupo de Estudio Latino Americano de Mieloma Múltiple).

The incidence of multiple myeloma (MM) has increased in the last 20 years, particularly in middle and low-middle income countries. Access to diagnostic and prognostic tests and the availability of effective care is highly variable globally. Latin America represents 10% of the world population, distributed in countries of varied size, population, and socio-economic development. In the last decade, great improvements have been made in the diagnosis and treatment of MM. Applying these advances in real life is a challenge in our region. Local data regarding MM standards of care and outcomes are limited. A survey was carried out among hematologists from 15 Latin American countries to describe access to MM diagnostic and prognostic tests and the availability of effective care options. This study provides real-world data for MM in our region, highlighting striking differences between public and private access to essential analyses and therapeutic options.

Linking nitrous oxide emissions to population dynamics of nitrifying and denitrifying prokaryotes in four full-scale wastewater treatment plants.

Ammonia-oxidizing bacteria (AOB), ammonia oxidizing archaea (AOA) and N2O-reducing denitrifiers were measured by quantitative real-time PCR (qPCR) in activated sludge samples from four full-scale wastewater treatment plants (WWTPs) in South Spain, and their abundances were linked to the generation of N2O in the samples using multivariate analysis (Non-metric multidimensional scaling, MDS, and BIO-ENV). The average abundances of AOA remained in similar orders of magnitude in all WWTPs (106 copies amoA/L activated sludge mixed liquor), while significant differences were detected for AOB (105-109copies amoA/L) and N2O-reducers (107-1010copies nosZ/L). Average N2O emissions measured in activated sludge samples ranged from 0.10 ±â€¯0.05 to 6.49 ±â€¯8.89 mg N2O-N/h/L activated sludge, and were strongly correlated with increased abundances of AOB and lower counts of N2O-reducers. A significant contribution of AOA to N2O generation was unlikely, since their abundance correlated negatively to N2O emissions. AOB abundance was favoured by higher NO3- and NO2-concentrations in the activated sludge.

The association between sleep quality, low back pain and disability: A prospective study in routine practice.

BACKGROUND: The objective of this study was to estimate the association between sleep quality (SQ) and improvements in low back pain (LBP) and disability, among patients treated for LBP in routine practice. METHODS: This prospective cohort study included 461 subacute and chronic LBP patients treated in 11 specialized centres, 14 primary care centres and eight physical therapy practices across 12 Spanish regions. LBP, leg pain, disability, catastrophizing, depression and SQ were assessed through validated questionnaires upon recruitment and 3 months later. Logistic regression models were developed to assess: (1) the association between the baseline score for SQ and improvements in LBP and disability at 3 months, and (2) the association between improvement in SQ and improvements in LBP and disability during the follow-up period. RESULTS: Seventy-three per cent of patients were subacute. Median scores at baseline were four points for both pain and disability, as assessed with a visual analog scale and the Roland-Morris Questionnaire, respectively. Regression models showed (OR [95% CI]) that baseline SQ was not associated with improvements in LBP (0.99 [0.94; 1.06]) or in disability (0.99 [0.93; 1.05]), although associations existed between 'improvement in SQ' and 'improvement in LBP' (4.34 [2.21; 8.51]), and 'improvement in SQ' and 'improvement in disability' (4.60 [2.29; 9.27]). CONCLUSIONS: Improvement in SQ is associated with improvements in LBP and in disability at 3-month follow-up, suggesting that they may reflect or be influenced by common factors. However, baseline SQ does not predict improvements in pain or disability. SIGNIFICANCE: In clinical practice, sleep quality, low back pain and disability are associated. However, sleep quality at baseline does not predict improvement in pain and disability.

Refining genomewide association for growth and fat deposition traits in an F pig population.

The identification of genomic regions that affect additive genetic variation and contain genes involved in controlling growth and fat deposition has enormous impact in the farm animal industry (e.g., carcass merit and meat quality). Therefore, a genomewide association study was implemented in an F pig population using a 60,000 SNP marker panel for traits related to growth and fat deposition. Estimated genomic EBV were linearly transformed to calculate SNP effects and to identify genomic positions possibly associated with the genetic variability of each trait. Genomic segments were then defined considering the markers included in a region 1 Mb up- and downstream from the SNP with the smallest -value and a false discovery rate < 0.05 for each trait. The significance for each 2-Mb segment was tested using the Bonferroni correction. Significant SNP were detected on SSC2, SSC3, SSC5, and SSC6, but 2-Mb segment significant effects were observed on SSC3 for weight at birth (wt_birth) and on SSC6 for 10th-rib backfat and last-rib backfat measured by ultrasound at different ages. Furthermore, a 6-Mb segment on SSC6 was also considered because the 2-Mb segments for 10 different fat deposition traits were overlapped. Although the segment effects for each trait remain significant, the proportion of additive variance explained by this larger segment was slightly smaller in some traits. In general, the results confirm the presence of genetic variability for wt_birth on SSC3 (18.0-20.2 Mb) and for fat deposition traits on SSC6 (133.8-136.0 Mb). Within these regions, fibrosin () and myosin light chain, phosphorylatable, fast skeletal muscle () genes could be considered as candidates for the wt_birth signal on SSC3, and the SERPINE1 mRNAbinding protein 1 gene () may be a candidate for the fat deposition trait signals on SSC6.

Meta-analysis of genome-wide association from genomic prediction models.

Genome-wide association (GWA) studies based on GBLUP models are a common practice in animal breeding. However, effect sizes of GWA tests are small, requiring larger sample sizes to enhance power of detection of rare variants. Because of difficulties in increasing sample size in animal populations, one alternative is to implement a meta-analysis (MA), combining information and results from independent GWA studies. Although this methodology has been used widely in human genetics, implementation in animal breeding has been limited. Thus, we present methods to implement a MA of GWA, describing the proper approach to compute weights derived from multiple genomic evaluations based on animal-centric GBLUP models. Application to real datasets shows that MA increases power of detection of associations in comparison with population-level GWA, allowing for population structure and heterogeneity of variance components across populations to be accounted for. Another advantage of MA is that it does not require access to genotype data that is required for a joint analysis. Scripts related to the implementation of this approach, which consider the strength of association as well as the sign, are distributed and thus account for heterogeneity in association phase between QTL and SNPs. Thus, MA of GWA is an attractive alternative to summarizing results from multiple genomic studies, avoiding restrictions with genotype data sharing, definition of fixed effects and different scales of measurement of evaluated traits.

Implementing meta-analysis from genome-wide association studies for pork quality traits.

Pork quality plays an important role in the meat processing industry. Thus, different methodologies have been implemented to elucidate the genetic architecture of traits affecting meat quality. One of the most common and widely used approaches is to perform genome-wide association (GWA) studies. However, a limitation of many GWA in animal breeding is the limited power due to small sample sizes in animal populations. One alternative is to implement a meta-analysis of GWA (MA-GWA) combining results from independent association studies. The objective of this study was to identify significant genomic regions associated with meat quality traits by performing MA-GWA for 8 different traits in 3 independent pig populations. Results from MA-GWA were used to search for genes possibly associated with the set of evaluated traits. Data from 3 pig data sets (U.S. Meat Animal Research Center, commercial, and Michigan State University Pig Resource Population) were used. A MA was implemented by combining -scores derived for each SNP in every population and then weighting them using the inverse of estimated variance of SNP effects. A search for annotated genes retrieved genes previously reported as candidates for shear force (calpain-1 catalytic subunit [] and calpastatin []), as well as for ultimate pH, purge loss, and cook loss (protein kinase, AMP-activated, γ 3 noncatalytic subunit []). In addition, novel candidate genes were identified for intramuscular fat and cook loss (acyl-CoA synthetase family member 3 mitochondrial []) and for the objective measure of muscle redness, CIE a* (glycogen synthase 1, muscle [] and ferritin, light polypeptide []). Thus, implementation of MA-GWA allowed integration of results for economically relevant traits and identified novel genes to be tested as candidates for meat quality traits in pig populations.

[How suitable is thromboembolism prophylaxis for patients with chronic auricular fibrillation at 3 primary care centers]. / Adecuación de la profilaxis tromboembólica en pacientes con fibrilación auricular crónica en 3 centros de atención primaria.

OBJECTIVE: To find just how suitable thromboembolism prophylaxis (TEP) is in a group of patients with chronic auricular fibrillation belonging to the primary care environment. DESIGN: Cross-sectional and descriptive multi-centre study. SETTING: The study was performed at 3 urban primary care centres in Madrid. PARTICIPANTS: All the patients recorded up to April 2001 with the diagnosis of chronic auricular fibrillation (n=274) were included. Patients with no clinical history or who had a valve prosthesis were excluded. MAIN MEASUREMENTS: Demographic variables, existence of factors of risk of embolism, presence of counter-indications for oral anti-coagulants, and the kind of thromboembolic prophylaxis taken were collected. RESULTS: A total of 274 patients were evaluated. Average age was 75 (SD, 9) and 52% were women. 82% of patients had at least one factor of risk of thromboembolism. The most commonly used kind of TEP was oral anti-coagulants. 45% of patients did not receive suitable TEP. 13.5% of patients at risk of embolism and who had no kind of TEP were found. CONCLUSIONS: There is a high percentage of patients with chronic auricular fibrillation and a high risk of embolism, who do not receive adequate TEP, in the absence of counter-indications to taking oral anticoagulants. There is great scope for improvement, which is within professionals' possibilities.

[Prescription of non-steroidal anti-inflammatories and gastric protectors in emergency service]. / Prescripción de antiinflamatorios no esteroideos y protectores gástricos en urgencias.

OBJECTIVES: To find the number of patients seen in casualty who received gastropathy prophylaxis with NSAIDs that complied with the pharmaco-therapeutic guidelines of the health district. DESIGN: Descriptive study of technical-scientific quality. SETTING: The Casualty Department of the Ramón y Cajal hospital. PARTICIPANTS: Randomised sample of 400 emergencies attended in January 1999 and 2000, excluding paediatric cases, people previously treated with gastro-protectors, patients admitted and the deceased. Main measurements. On the basis of casualty records: suitability of indication and criteria used; if unsuitable, how; adequacy of selection of the principle, patient' age and sex, digestive pathology history, area and year of care. RESULTS: NSAIDs were prescribed in 37.9% of cases (33.27-42.79), with prescription unsuitable in 21.19% (15.2-28.3). 15% (9.5-22) were unsuitable by default; and 54.2% (35.1-72.1), by excess. Unsuitability was greater among women, if there was history of digestive pathology, and among older people, with no differences found for area or year of care. The choice of gastric protector was not suitable in any case. CONCLUSIONS: Given the amount of primary care prescription originating in hospital casualty departments, and its effect on the training of family medicine interns, strategies coordinated between health care levels must be introduced in order to improve gastric protection prescription in NSAID gastropathy prophylaxis. The effectiveness of these strategies must be evaluated.

Prescripción de antiinflamatorios no esteroideos y protectores gástricos en urgencias / Prescription of non-steroidal anti-inflammatories and gastric protectors in casualty

Objetivos. Conocer la proporción de pacientes atendidos en urgencias en los que se hace profilaxis de gastropatía por aintiinflamatorios no esteroideos (AINE) de forma adecuada a la guía farmacoterapéutica del área sanitaria. Diseño. Estudio descriptivo de la calidad científico-técnica. Emplazamiento. El Servicio de Urgencias del hospital Ramón y Cajal. Participantes. Muestra aleatoria de 400 urgencias atendidas en enero de 1999 y de 2000 en la que no se incluyen a los pacientes en edades pediátricas, en tratamiento previo con gastroprotectores, ingresados y fallecidos. Mediciones principales. A partir de la hoja de urgencias se determinaron la adecuación de la indicación y los criterios utilizados, el tipo de inadecuación, la adecuación de la selección del principio, la edad y el sexo del paciente, los antecedentes de enfermedades digestivas, el área y el año de atención. Resultados. Se prescribió AINE a un 37,9 por ciento de los casos (33,27-42,79 por ciento), fue inadecuada la prescripción de gastroprotección en un 21,19 por ciento (15,2-28,3 por ciento): inadecuación por defecto del 15 por ciento (9,5-22 por ciento) e inadecuación por exceso del 54,2 por ciento (35,1-72,1 por ciento). El porcentaje de inadecuación fue mayor entre las mujeres, si había antecedentes de enfermedades digestivas y entre las personas más mayores, no encontrándose diferencias en relación con el área o el año de atención. En ningún caso la selección del fármaco gastroprotector fue adecuada. Conclusiones. Dada la importancia en atención primaria de la prescripción inducida desde las urgencias hospitalarias y su influencia en la formación de residentes de medicina de familia, es necesario implantar estrategias coordinadas entre niveles asistenciales de mejora de la prescripción de gastroprotección para la profilaxis de gastropatía por AINE, siendo imprescindible la evaluación de la efectividad de dichas estrategias. (AU)

Estudio descriptivo del cribado del cáncer de cérvix en nuestrocentro de salud. No captamos a la población de riesgo / Descriptive study of cervix cancer screening in our Primary Health Care center: we do not accede the risk population

Fundamentos: la población inmigrante está aumentando en nuestro país y en nuestra zona de salud, y es una población con más riesgo para desarrollar cáncer de cérvix que la población española, así, nos planteamos la posibilidad de conocer cuál es la situación del cribado del cáncer de cérvix en esta población y compararla con la población local. Objetivo: comparar el porcentaje de realización de citología vaginal entre la población inmigrante latinoamericana y la población local de un centro de salud. Diseño: estudio observacional descriptivo transversal. Material y métodos: en un centro de salud urbano, se estudió una muestra de 153 mujeres inmigrantes latinoamericanas y 153 mujeres españolas (muestra apareada por edad) de 18 a 65 años, de las que se recogieron datos sociodemográficos y de la asistencia al centro y datos sobre la realización de citología y frecuencia. Se analizaron los datos por comparación de porcentajes y Chicuadrado. Resultados: se encontraron diferencias significativas entre ambos grupos en el porcentaje de mujeres que se había realizado citología (25,5 por ciento inmigrantes frente a 43,8 por ciento no inmigrantes). También entre las que no se la habían realizado (58,8 frente a 41,2 por ciento). En los distintos intervalos etarios sólo hubo diferencias en el de 30 a 39 años. Conclusiones: dado que las mujeres inmigrantes presentan un porcentaje menor de realización de citologías deberíamos plantearnos la manera de mejorar dicha cobertura en esta población inmigrante, ya que al tener una incidencia más alta de cáncer de cérvix se puede beneficiar más del programa de cribado que la población española (AU)

[New paradigms in the regulation of bone metabolism]. / Nuevos paradigmas en la regulación del metabolismo óseo.

Although multiple hormones and cytokines regulate various aspects of osteoclast formation, the two final effectors, osteoprotegerin (OPG) and its ligand (OPGL/RANKL) have been recently identified. Since then, there have been important advances in the understanding of the molecular mechanisms that regulate the crosstalk between osteoblasts/stromal and hematopoietic osteoclast precursor cells. In this article, we describe the new concepts from the identification of OPG, a protein with potent osteoclastogenesis inhibitory activity, to the isolation of RANKL, a transmembrane ligand expressed on osteoblasts/stromal cells that bind to RANK, a transmembrane receptor on osteoclast cells and its precursors. The interaction between RANK and RANKL triggers a series of mechanisms that result in differentiation, maturation and activation of osteoclasts. OPG inhibits osteoclastogenesis binding to RANKL and blocks its interaction with RANK. Many hormones and cytokines, like PTH and IL-11, act inhibiting production of OPG and stimulating production of RANKL. Contrary to this, estrogens inhibit production of RANKL and RANKL-stimulated osteoclastogenesis. The knowledge of the RANK/RANKL/OPG system and the understanding of osteoclast differentiation and activation has had a great impact on the field of bone metabolism, with new possible treatment strategies for diseases characterized by excessive bone resorption.

Cribado del cáncer de cérvix: ¿la misma frecuencia para mujeres inmigrantes latinoamericanas? / Screening for cervix cancer: same incidence in latinoamerican immigrants women?

Debido al cambio demográfico que está viviendo nuestro país con la llegada de inmigrantes de diferentes nacionalidades, nos preguntamos si estos nuevos usuarios del Sistema Nacional de Salud presentan los mismos o diferentes problemas de salud que la población autóctona. En particular en este artículo nos planteamos si las mujeres provenientes de América del Sur, población mayoritaria de inmigrantes en nuestra zona de salud, presentan diferente riesgo de padecer cáncer de cuello uterino, y por ello precisan cambios en el programa de cribado. Buscando información en la literatura no hemos encontrado evidencias de que sea necesario variar los intervalos en el programa de screening , pese a que existen diferencias en la prevalencia y en algunos factores de riesgo para esta enfermedad (AU)

Reordenamiento de inmunoglobulinas en el diagnóstico diferencial del linfoma gástrico primario / Immunoglobulin rearrangement in the differential diagnosis of primary gastric lymphoma

Background: The traditional methods to distinguish Chronic Follicular Gastritis and Primary Gastric Lymphoma do not allow an adequate definitive diagnosis in a significant number of cases. The Molecular Biology diagnostic methods are based on the rearrangement of immunoglobulin genes. The polymerase chain reaction (PCR) specifically amplifies this rearrangement and allows molecular analysis of minimal tissue samples obtained with endoscopical biopsies. Aim: To test the usefulness of this PCR method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma. Material and methods: We analyzed the endoscopical biopsies of six Chronic Follicular Gastritis cases and eight surgically treated Primary Gastric Lymphoma cases, six with the correct diagnosis in the endoscopical biopsies and two with a diagnosis of Chronic Follicular Gastritis. Results: A policlonal immunoglobulin rearrangement was found in the six cases with Chronic Follicular Gastritis. A monoclonal arrangement was found in 5 of 6 biopsies with the diagnosis of Primary Gastric Lymphoma. The same monoclonal rearrangement was observed in the two biopsies incorrectly diagnosed as Chronic Follicular Gastritis. Conclusions: PCR analysis of immunoglobulin rearrangement is a useful method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma