Comparative analysis between 2 periods of acute myocardial infarction after a decade in Mallorca. IBERIA Study (996-1998) and Infarction-Code (2008-2010). / Análisis comparativo de 2 registros de infarto agudo de miocardio tras una década de cambios. Estudio IBERICA (1996-1998) y Código Infarto-Illes Balears (2008-2010).

OBJECTIVE: To investigate the differences in mortality at 28 days and other prognostic variables in 2 periods: IBERICA-Mallorca (1996-1998) and Infarction Code of the Balearic Islands (IC-IB) (2008-2010). DESIGN: Two observational prospective cohorts. SETTING: Hospital Universitario Son Dureta, 1996-1998 and 2008-2010. PATIENTS: Acute coronary syndrome with ST elevation of≤24h of anterior and inferior site. MAIN VARIABLES OF INTEREST: Age, sex, cardiovascular risk factors, site of AMI, time delays, reperfusion therapy with fibrinolysis and primary angioplasty, administration of acetylsalicylic acid, beta blockers and angiotensin converting enzyme inhibitors. Killip class, malignant arrhythmias, mechanical complications and death at 28 days were included. RESULTS: Four hundred and forty-two of the 889 patients included in the IBERICA-Mallorca and 498 of 847 in the IC-IB were analyzed. The site and Killip class on admission were similar in both cohorts. The main significant difference between IBERICA and IC-IB group were age (64 vs. 58 years), prior myocardial infarction (17.9 vs. 8.1%), the median symtoms to first ECG time (120 vs. 90min), median first ECG to fibrinolysis time (60 vs. 35min), fibrinolytic therapy (54.8 vs. 18.7%), patients without revascularization treatment (45.9 vs. 9.2%), primary angioplasty (1.0% vs. 92.0%). The mortality at 28 days was lower in the IC-IB (12.2 vs. 7.2%; hazard ratio 0.560; 95% CI 0.360-0.872; P=.010). CONCLUSION: The 28-day mortality in acute coronary syndrome with ST elevation in Mallorca has declined in the last decade, basically due to increased reperfusion therapy with primary angioplasty and reducing delays time to reperfusion.

Bioassessment of trace element contamination of Mediterranean coastal waters using the seagrass Posidonia oceanica.

A large scale survey of the trace element (TE) contamination of Mediterranean coastal waters was performed from the analysis of Ag, As, Cd, Cu, Hg, Ni and Pb in the bioindicator Posidonia oceanica, sampled at 110 sites differing by their levels of exposure to contaminants. The holistic approach developed in this study, based on the combined utilization of several complementary monitoring tools, i.e. water quality scale, pollution index and spatial analysis, accurately assessed the TE contamination rate of Mediterranean coastal waters. In particular, the mapping of the TE contamination according to a new proposed 5-level water quality scale precisely outlined the contamination severity along Mediterranean coasts and facilitated interregional comparisons. Finally, the reliability of the use of P. oceanica as bioindicator species was again demonstrated through several global, regional and local detailed case studies. NB: The designations employed and the presentation of the information in this document do not imply the expression of any opinion whatsoever on the part of the authors concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

Multiorgan failure in the serious trauma patient.

Multiorgan failure remains one of the leading causes of late morbidity and mortality after severe trauma. In the early phase, it is related with an uncontrolled hyper-inflammation state, whereas in the late phase (>72 h), septic complications play a major role. We review the underlying pathophysiology, the evaluation with different scales and the clinical factors associated with multiorgan failure, as well as potential treatment options.

[Impact of the COVID-19 pandemic on patient safety incident and medication error reporting systems]. / Impacto de la pandemia COVID-19 en los sistemas de notificación de incidentes de seguridad del paciente y errores de medicación.

BACKGROUND AND AIM: To determine the impact of the COVID-19 pandemic on the epidemiology of safety incidents (SI) and medication errors (ME) reported to the CISEMadrid notification system in the hospital and primary care settings of the Madrid Health Service (SERMAS). MATERIALS AND METHODS: Observational and descriptive study with a retrospective analysis of data including all CISEMadrid notifications from 01-Jan-2018 to 31-Dec-2020, from 33 hospitals and 262 health care centres of the SERMAS. The two periods in 2020 with the greatest increase in COVID-19 cases were identified to compare incidents reported in the pre-pandemic and pandemic periods. RESULTS: 36,494 incidents were reported. Comparing both periods, an overall decrease in pandemic notifications of 60.7% was observed, being higher in primary care, falling to 33% of previous levels. The reduction in notifications was similar in the peaks and valleys of the waves. The three most frequent SIs in both periods and care settings were: diagnostic tests, medical devices/equipment/clinical furniture and organisational management/citations. In ME, dose failure and inappropriate selection were the most frequent in both settings and periods. There were no relevant differences in patient consequences in both periods. CONCLUSIONS: During the pandemic, patient safety notifications decreased although the most frequent types remained the same, as did their impact on the patient, both in hospitals and in primary care. The safety culture of organisations is a critical aspect for the maintenance of reporting systems.

A single primer pair gives a specific ortholog amplicon in a wide range of Cyanobacteria and plastid-bearing organisms: applicability in inventory of reference material from collections and phylogenetic analysis.

The scarcity of universally applied molecular markers for algae has resulted in the development of multiple, independent and not easily comparable systems. The goal of this work is to increase the number of available molecular markers and to generate easily comparable systems. Thereby, we have designed a primer pair capable of amplifying a broad range of organisms: Cyanobacteria, Chlorophyta, Chlorarachniophyta, Cryptophyta, Euglenida, Glaucophyta, Rhodophyta, Stramenopiles and Streptophyta including plants. This primer pair can amplify a portion of the 23S rRNA gene with sufficient variability to identify reference material form collections across a broad range of taxa and perform phylogenetic studies alongside other available markers.

[Hemodynamic variability caused by pressure-volume plotting and alveolar recruitment maneuvers in patients with adult respiratory distress syndrome]. / Variaciones hemodinámicas inducidas por la realización de una curva presión-volumen y una maniobra de reclutamiento alveolar en pacientes con síndrome de distrés respiratorio agudo.

OBJECTIVES: The plotting of pressure-volume curves and the performance of alveolar recruitment maneuvers are common practices in the care of patients with adult respiratory distress syndrome (ARDS), even though potentially harmful hemodynamic effects are associated with sustaining a high intrathoracic pressure. Our aim was to analyze hemodynamic and ventilatory changes related to these 2 maneuvers and to assess the short-term effectiveness of recruitment. PATIENTS AND METHODS: The patients had ARDS and were being monitored with a catheter connected to a PiCCO system. All measurements were taken in sinus rhythm and with adequate vascular filling. Values recorded during plotting of the quasistatic pressure-volume curve and the recruitment maneuver (sustained airway pressure of 40 cm H2O) were the cardiac index, mean arterial pressure, heart rate, systolic volume index, and oxygen saturation (SpO2). Blood gas measurements were recorded before the maneuvers and 15 minutes afterwards. RESULTS: All parameters decreased significantly in the 14 patients studied. The mean (SD) maximum decreases, from which all patients recovered within 2 minutes, were as follows: cardiac index, 26% (16%); mean arterial pressure, 6% (6%); heart rate, 4% (5%), systolic volume index, 21% (15%); and SpO2, 3% (3%). Significant increases in PaO2 (7% [6%]) and the ratio of PaO2 to the fraction of inspired oxygen were recorded after the recruitment maneuver (P=.016 and P=.014, respectively), but the changes were not clinically significant. CONCLUSIONS: The hemodynamic disturbances associated with the alveolar recruitment maneuver based on sustaining a high end-expiratory pressure and the minor improvement in oxygenation achieved as a result suggest that the routine use of that maneuver in ARDS patients is of questionable value.

[EFQM Model in the hospitals of Madrid Regional Health Service: full self-assessment cycle]. / Modelo EFQM en los hospitales del Servicio Madrileño de Salud: ciclo completo de autoevaluación.

AIM: To analyse a complete cycle of self-assessment using the European Foundation for Quality Management (EFQM) Model in the hospitals of the Madrid Health Service as regards the fundamental concepts of excellence (FCE). METHOD: Descriptive study of the EFQM self-assessments of the entire public hospital sector identifying the methodology and the information on strengths, weaknesses, evidence, RADAR matrix (Results, Approach, Deployment, Assessment and Review), and the related FCEs in the enabling criteria and in the prioritised action plans. RESULTS: The self-assessment was carried out in 85% of the hospitals (29/34), 86% of them required specific training (25/29), with a total of 329 teaching hours and 833 people in training. Multidisciplinary working groups were required in 83% of the hospitals (24/29), with 123 groups and 857 people involved. There were 3,686 strengths and 3,197 weaknesses identified: strengths and weaknesses were 78% (2,869) and 74% (2,355), respectively, for the enabling criteria and 22% (817) and 26% (842), respectively, for the results criteria. The mean score was 404 points with a median of 399. The main FCEs were managing with agility, developing organisational capability, sustaining outstanding results, creating a sustainable future, succeeding through the talent of people, and adding value for customers, with harnessing creativity/innovation and leading with vision, inspiration and integrity being placed in lower positions. A total of 113 action plans were identified for all the hospitals. CONCLUSION: A complete EFQM self-assessment cycle of the entire public hospital sector of a Regional Health Service is provided, linking the analysis and action plans with the FCE of the EFQM Model.

Assessing the competences associated with a nursing Bachelor thesis by means of rubrics.

BACKGROUND: Writing a Bachelor thesis is the last step in obtaining a university degree. The thesis may be job- or research-orientated, but it must demonstrate certain degree-level competences. Rubrics are a useful way of unifying the assessment criteria. OBJECTIVES: To design a system of rubrics for assessing the competences associated with the Bachelor thesis of a nursing degree, to examine the system's reliability and validity and to analyse results in relation to the final thesis mark. DESIGN: Cross-sectional and psychometric study conducted between 2012 and 2014. SETTINGS: Nursing degree at a Spanish university. PARTICIPANTS: Twelve tutors who designed the system of rubrics. Students (n = 76) who wrote their Bachelor thesis during the 2013-2014 academic year. METHODS: After deciding which aspects would be assessed, who would assess them and when, the tutors developed seven rubrics (drafting process, assessment of the written thesis by the supervisor and by a panel, student self-assessment, peer assessment, tutor evaluation of the peer assessment and panel assessment of the viva). We analysed the reliability (inter-rater and internal consistency) and validity (convergent and discriminant) of the rubrics, and also the relationship between the competences assessed and the final thesis mark. RESULTS: All the rubrics had internal consistency coefficients >0.80. The rubric for oral communication skills (viva) yielded inter-rater reliability of 0.95. Factor analysis indicated a unidimensional structure for all but one of the rubrics, the exception being the rubric for peer assessment, which had a two-factor structure. The main competences associated with a good quality Bachelor thesis were written communication skills and the ability to work independently. CONCLUSION: The assessment system based on seven rubrics is shown to be valid and reliable. Writing a Bachelor thesis requires a range of degree-level competences and it offers nursing students the opportunity to develop their evidence-based practice skills.

Integrating genomic alterations in diffuse large B-cell lymphoma identifies new relevant pathways and potential therapeutic targets.

Genome studies of diffuse large B-cell lymphoma (DLBCL) have revealed a large number of somatic mutations and structural alterations. However, the clinical significance of these alterations is still not well defined. In this study, we have integrated the analysis of targeted next-generation sequencing of 106 genes and genomic copy number alterations (CNA) in 150 DLBCL. The clinically significant findings were validated in an independent cohort of 111 patients. Germinal center B-cell and activated B-cell DLBCL had a differential profile of mutations, altered pathogenic pathways and CNA. Mutations in genes of the NOTCH pathway and tumor suppressor genes (TP53/CDKN2A), but not individual genes, conferred an unfavorable prognosis, confirmed in the independent validation cohort. A gene expression profiling analysis showed that tumors with NOTCH pathway mutations had a significant modulation of downstream target genes, emphasizing the relevance of this pathway in DLBCL. An in silico drug discovery analysis recognized 69 (46%) cases carrying at least one genomic alteration considered a potential target of drug response according to early clinical trials or preclinical assays in DLBCL or other lymphomas. In conclusion, this study identifies relevant pathways and mutated genes in DLBCL and recognizes potential targets for new intervention strategies.

A B-cell epigenetic signature defines three biologic subgroups of chronic lymphocytic leukemia with clinical impact.

Prospective identification of patients with chronic lymphocytic leukemia (CLL) destined to progress would greatly facilitate their clinical management. Recently, whole-genome DNA methylation analyses identified three clinicobiologic CLL subgroups with an epigenetic signature related to different normal B-cell counterparts. Here, we developed a clinically applicable method to identify these subgroups and to study their clinical relevance. Using a support vector machine approach, we built a prediction model using five epigenetic biomarkers that was able to classify CLL patients accurately into the three subgroups, namely naive B-cell-like, intermediate and memory B-cell-like CLL. DNA methylation was quantified by highly reproducible bisulfite pyrosequencing assays in two independent CLL series. In the initial series (n=211), the three subgroups showed differential levels of IGHV (immunoglobulin heavy-chain locus) mutation (P<0.001) and VH usage (P<0.03), as well as different clinical features and outcome in terms of time to first treatment (TTT) and overall survival (P<0.001). A multivariate Cox model showed that epigenetic classification was the strongest predictor of TTT (P<0.001) along with Binet stage (P<0.001). These findings were corroborated in a validation series (n=97). In this study, we developed a simple and robust method using epigenetic biomarkers to categorize CLLs into three subgroups with different clinicobiologic features and outcome.

Lymphocyte homing in mice: lack of significant alteration when H-2 antigen expression is moderately modified.

The part played by MHC antigens on lymphocyte homing has been investigated by inducing modifications of their expression on lymphoid cells. A significant, though moderate, enhancement of H-2 antigen expression has been observed following in vitro treatment of lymphocytes with alpha-IFN. A decrease has been obtained after in vivo treatment of mice with chloramphenicol. These rather moderate alterations of H-2 density (ca. 20-30%, as determined by cytofluorometry) did not induced changes of lymphocyte capacity to home into the different lymphoid organs.

Effect of sucralfate on gastric intramucosal pH in critically ill patients.

OBJECTIVE: To determine whether sucralfate administration affects the tonometric measurement of gastric intramucosal pH (pHi). DESIGN: Non-randomized observational study. SETTING: General intensive care unit of a teaching hospital. PATIENTS: Twenty critically ill, mechanically ventilated, consecutively admitted patients requiring an arterial catheter and nasogastric tube. INTERVENTIONS: Tonometer placement and sucralfate administration. MEASUREMENTS AND MAIN RESULTS: We simultaneously determined tonometer saline PCO2 (PCO2i), arterial blood gases, pH of gastric juice and pHi. These parameters were evaluated immediately before sucralfate administration, and 2 h and 4 h after. We did not detect any change in either PCO2i or pHi after sucralfate administration (PCO2i: basal 6.4 +/- 1.7, 2 h 6.3 +/- 1.7, 4 h 6.3 +/- 1.7; pHi: basal 7.35 +/- 0.13, 2 h 7.36 +/- 0.12, 4 h 7.36 +/- 0.12). CONCLUSIONS: Sucralfate does not affect the tonometric measurement of PCO2i and pHi.

Effect of ranitidine on gastric intramucosal pH in critically ill patients.

OBJECTIVE: To determine whether ranitidine a) increases the values of gastric intramucosal pH (pHi) in critically ill patients, as determined by tonometry; b) reduces the variability of these measurements. DESIGN: Prospective, double blind, randomized, placebo-controlled study. SETTING: General Intensive Care Unit of a teaching hospital. PATIENTS: Twenty-five critically ill, mechanically ventilated patients requiring arterial catheter and nasogastric tube. INTERVENTIONS: Tonometer placement; blind, random administration of intravenous ranitidine (50 mg) or placebo. MEASUREMENTS AND MAIN RESULTS: Tonometer saline PCO2 (PCO2i), arterial blood gases, gastric juice pH and pHi were determined immediately before, and 2, 4, 6 and 8 h after, ranitidine (12 patients) or placebo (13 patients). Ranitidine significantly increased gastric juice pH, but did not affect PCO2i or pHi; pHi was 7.34 +/- 0.14 before ranitidine, and 7.30 +/- 0.12, 7.31 +/- 0.11, 7.31 +/- 0.14 and 7.31 +/- 0.12-2, 4, 6 and 8 h, respectively, after ranitidine administration (p = 0.55). Ranitidine did not modify the coefficients of variation of PCO2i or pHi, either. No significant changes in gastric juice pH, PCO2i or pHi were observed in the placebo group. CONCLUSIONS: In critically ill patients, ranitidine has no effect on pHi values, and does not increase the reproducibility of pHi measurements.

"Moya-moya' disease caused by cranial trauma.

A case of "moya-moya" disease of a 12-year-old boy is reported. The clinical history started at 3 years 2 months after cranial trauma. The patient developed mental retardation, hemiparesis and seizures.

[Patients with end-stage chronic renal insufficiency on programmed withdrawal from dialysis]. / Pacientes con insuficiencia renal crónica terminal retirados de diálisis bajo protocolización.

UNLABELLED: The voluntary discontinuation of dialysis by patients is a common mode of death in dialysis programmes. Unfortunately the Spanish experience has not been related in the nephrological literature. Initiation of, and withdrawal from, dialysis pose ethical questions for medicine in the 21st century. The dialysis population is aging and they have multiple medical problems. The choice may be between prolongation of quantity or quality of life. We evaluated a protocol for initiation of dialysis in patients with end stage renal failure and their subsequent withdrawal. We determined the factors predicting withdrawal of dialysis and revised the protocol to take account of these. We carried out an opinion poll of doctors and nurses about the effectiveness of the protocol. We studied prospectively the reasons for death of patients in the last seven years. RESULTS: Thirty patients were withdrawn from dialysis out of 116 who died during treatment by hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) in the last seven years. Vascular nephropathy is the principal disease predicting withdrawal from dialysis; the main precipitating cause is mental incapacity. The availability of a protocol for withdrawal of dialysis is well received by doctors and nurses and it engenders moral and legal calm when facing difficult decisions. Twenty-six per cent of deaths on regular dialysis are the result of withdrawal of treatment.

[Bilateral serous retinal detachments in acute posterior multifocal placoid pigmentous epitheliopathy]. / Desprendimientos retinianos serosos bilaterales en la epiteliopatía pigmentaria placoide multifocal posterior aguda.

PURPOSE/METHOD: A particular subtype of acute posterior multifocal placoid pigmented epitheliopathy (APMPPE), different from the classical Gass description, is presented. A 22 year old woman who suffered a sudden decrease in visual acuity associated to bilateral serous retinal detachment concurrent with anterior uveitis is studied. We remark the fact that patient had been using contraceptives and antibiotics (norfloxacin) for the past two months prior to first visit. One month later, visual acuity does not show any recovery. A corticosteroid treatment is prescribed showing improvement. RESULTS/CONCLUSIONS: We believe that although APMPPE usually resolves spontaneously, treatment is needed for clinical subtypes involving serous retinal detachment.

[Giving up the tobacco habit through the application of the Smoker's Aid Program in the Chantrea Health Centre]. / Abandono del hábito tabáquico mediante la aplicación del programa de ayuda al fumador en el centro de salud de Chantrea.

INTRODUCTION: This is a prospective descriptive study of intervention without aleatory assignation, carried out in the Chantrea Health Centre. Its aim is to determine the characteristics of the smokers who are taking part in two interventions by the Smokers' Aid Program (Programa de Ayuda al Fumador-PAF), and to evaluate the factors that influence the latter's success. MATERIAL AND METHODS: The characteristics of 100 smokers were analyzed. They were offered one of the two PAF interventions: Minimal Intervention 1 (MN1): they are given a support brochure in the first consultations, contacted by telephone after one month and called to consultation after 6 months to measure CO. Minimal Intervention 2 (MN2): the smoker makes 5 consultations of support in giving up smoking (+ or - nicotine patches) with the doctor, nurse or social worker indiscriminately. The factors that were influential in abandoning the habit with 65 subjects were evaluated. RESULTS: 60% of the subjects were male with an average age of 41 (DE 29). 29% showed a pathology related to tobacco, with no relation found between this and the success of the interventions. Those who chose MN2 (38%) had started tobacco consumption at an earlier age and were more dependent on nicotine. Of the 65 smokers who completed the program, 37% continued not to smoke after 6 months. Those who managed to give up smoking were of a greater average age, had spent more years smoking and belonged above all to the MN1 intervention. DISCUSSION: Notable successes are achieved if the actions are carried out by the First Aid Team. We find no significant differences between the characteristics of those who give up smoking and those who do not. Not even a serious pathology, related to tobacco, is predictive of success. The smoker's dependence on nicotine must be taken into account in the intervention.

Variability in glutenin subunit composition of Mediterranean durum wheat germplasm and its relationship with gluten strength.

The allelic composition at five glutenin loci was assessed by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (1D SDS-PAGE) on a set of 155 landraces (from 21 Mediterranean countries) and 18 representative modern varieties. Gluten strength was determined by SDS-sedimentation on samples grown under rainfed conditions during 3 years in north-eastern Spain. One hundred and fourteen alleles/banding patterns were identified (25 at Glu-1 and 89 at Glu-2/Glu-3 loci); 0·85 of them were in landraces at very low frequency and 0·72 were unreported. Genetic diversity index was 0·71 for landraces and 0·38 for modern varieties. All modern varieties exhibited medium to strong gluten type with none of their 13 banding patterns having a significant effect on gluten-strength type. Ten banding patterns significantly affected gluten strength in landraces. Alleles Glu-B1e (band 20), Glu-A3a (band 6), Glu-A3d (bands 6 + 11), Glu-B3a (bands 2 + 4+15 + 19) and Glu-B2a (band 12) significantly increased the SDS-value, and their effects were associated with their frequency. Two alleles, Glu-A3b (band 5) and Glu-B2b (null), significantly reduced gluten strength, but only the effect of the latter locus could be associated with its frequency. Only three rare banding patterns affected gluten strength significantly: Glu-B1a (band 7), found in six landraces, had a negative effect, whereas banding patterns 2 + 4+14 + 15 + 18 and 2 + 4+15 + 18 + 19 at Glu-B3 had a positive effect. Landraces with outstanding gluten strength were more frequent in eastern than in western Mediterranean countries. The geographical pattern displayed from the frequencies of Glu-A1c is discussed.

[Barriers and challenges of the functional healthcare risk management units in hospitals of Madrid health service]. / Barreras y retos de las unidades funcionales de gestión de riesgos sanitarios en los hospitales del Servicio Madrileño de Salud.

OBJECTIVE: To identify the barriers and challenges for the effective development of risk management units in hospitals of the Madrid Health Service. MATERIAL AND METHODS: Descriptive cross-sectional study aimed at the management teams and members of the functional units of 31 hospitals in the Madrid Health Service. A self-administered questionnaire requesting answers in free text was used, identifying up to five barriers and challenges, and their prioritization by awarding from 1-5 points according to their importance. A discourse analysis was then conducted, grouping common themes and sorting them according to their score. RESULTS: The overall response rate was 94%. The most frequently identified barriers were lack of time (21%), inadequate safety culture (13%), lack of publication of their activities (10%), and lack of training (10%). The most important challenge was developing the training (18%), followed by improving the culture (17%), communication of safety activities (11%), and achieve leadership from the managers of the services (11%). CONCLUSIONS: According to the study conditions, the main identified barrier identified was the lack of available time, and the principal challenge found was promoting a proactive learning culture.

Genetic improvement of bread wheat yield and associated traits in Spain during the 20th century.

A collection of 26 wheat genotypes widely grown in Spain during the 20th century was evaluated in eight contrasting environments in order to quantify breeding achievements in yield and associated traits. From 1930 to 2000, yield increased at a rate of 35·1 kg/ha/yr or 0·88%/yr, but estimations of relative genetic gain (RGG) were environment-dependent. RGG estimated for yield were positively associated with the average minimum daily temperatures from sowing to heading in the testing environments (R(2) = 0·81; P < 0·01). The number of grains/spike and the number of spikes/m(2) increased at a rate of 0·60%/yr and 0·30%/yr, respectively, while grain weight remained unchanged. The present study detected two main episodes of yield improvement during the century. The first one coincided with the introduction, during the 1950s, of the first improved cultivars derived from intra-specific crosses, which increased the yield of landraces by 30% due to an increase of c. 58% in the number of grains/spike, accompanied by a 16% reduction in grain weight. These initial cultivars (termed 'old-bred' in a previous study by Sanchez-Garcia et al. 2012) exhibited a higher harvest index (HI), increased from 0·25 to 0·40, but maintained the same aboveground biomass at maturity as the landraces (despite reducing both plant height and the number of tillers/plant) due to increases in the proportion of tillers bearing spikes. The second yield gain occurred after the introduction, in the early 1970s, of semi-dwarf germplasm from CIMMYT (International Maize and Wheat Improvement Centre) and some French cultivars. This new germplasm further reduced plant height, improved HI up to 0·45 and increased the number of tillers/plant while maintaining their rate of fertility, thus resulting in a yield gain of c. 37%. The cultivars released during the last decade of the century did not contribute to significant yield improvements.