Intra-His bundle block: clinical, electrocardiographic, and electrophysiologic characteristics

OBJECTIVE: To assess the clinical, electrocardiographic, and electrophysiologic characteristics of patients (pt) with intra-His bundle block undergoing an electrophysiologic study (EPS). METHODS: We analyzed the characteristics of 16 pt with second-degree atrioventricular block and symptoms of syncope or dyspnea, or both, undergoing conventional EPS. RESULTS: Intra-His bundle block was documented in 16 pt during an EPS. In 15 (94%) pt, the atrioventricular block was recorded in sinus rhythm; 4 (25%) pt had intra-His Wenckebach phenomenon, which correlated with Mobitz I (MI) atrioventricular block on the electrocardiogram. Seven (44%) pt had 2:1 atrioventricular block, 2 of whom were asymptomatic (12.5%). One (6%) pt had intra- and infra-His bundle block. Clinically, 11 (68%) pt had syncope or presyncope, 3 (18%) had dyspnea on exertion, and 2 (12.5%) were asymptomatic. Eight (50%) pt had bundle-branch block as follows: 4 (25%) pt had left bundle-branch block, and 4 (25%) had right bundle-branch block. Left anterosuperior divisional block was observed in 3 pt (19%), 2 of whom with associated right bundle-branch block. CONCLUSION: Intra-His bundle block was observed in 11% of the pt with second-degree atrioventricular block, syncope or presyncope, or both, it being the most frequent clinical presentation. Intra-His bundle block was more common in the elderly (> 60 years) and among females. The most frequent electrocardiographic presentations were second-degree Mobitz I or type 2:1 atrioventricular block.

Effect of arginine vasopressin on the canine epicardial coronary artery: experiments on V1-receptor-mediated production of nitric oxide

OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.

Kawasaki disease: involution of giant coronary aneurysms after prolonged anti-inflammatory treatment

The patient is a 5-year-old male with Kawasaki disease, whose involution of giant aneurysms of the left coronary arteries was surprising after a prolonged period of treatment, which lasted 80 uninterrupted days and comprised anti-inflammatory drugs associated with anticoagulation agents. The distal diameters of the anterior interventricular, the diagonal, and the circumflex arteries normalized by the end of the treatment. A residual giant aneurysm localized at the beginning of the anterior interventricular artery did not cause ischemia. Continuation of the medication for a prolonged period was recommended.

Frequency of hypertension in chronic Chagas' disease: retrospective clinical study

OBJECTIVE: To assess the frequency of hypertension in chagasic patients, as well as its clinical behavior and cardiologic findings. METHODS: We carried out a retrospective study with 225 patients with chronic Chagas' disease and hypertension (104 males), mean age of 55.1 ± 11.8. These patients were being followed up in the outpatient care clinics from 1984 to 2000. The study assessed the clinical, electrocardiographic, and radiological viewpoints. RESULTS: Of the 225 hypertensive patients (prevalence = 33.3%), 78 (34.7%) had mild hypertension, 108 (48%) had moderate hypertension, and 39 (17.3%) had severe hypertension. The association of left anterosuperior divisional block and right bundle-branch block occurred in 39 cases (17.3%), and enlargement of the cardiac area on radiological examination occurred in 93 (44.9%) of the 207 cases studied. The undetermined form of Chagas' disease was the most prevalent, 30.2% of the cases, followed by the form associated with conduction disorders in 27.1%, and the isolated form of conduction disorders in 21.3%. CONCLUSION: Chagasic patients had a frequency of hypertension similar to that of the general population, and the clinical profile of the hypertensive chagasic patients seemed not to differ a lot from that of the chagasic patients.

Relatório de estágio profissionalizante em psicomotricidade em vertente educacional no Centro de Apoio Psicopedagógico do Funchal

Este documento descreve o trabalho implementado no Centro de Apoio psicopedagógico do Funchal, no âmbito do Ramo de Aprofundamento de Competências Profissionais do mestrado em Reabilitação Psicomotora, durante o ano letivo 2013/2014. O trabalho desenvolvido centrou-se nas áreas da Psicomotricidade, numa dinâmica de intervenção individual e em grupo, com treze crianças com Perturbações do Desenvolvimento, contendo a mais nova quatro anos e a mais velha onze. A intervenção seguiu uma organização lógica e coerente passando pelas avaliações, planos de intervenção, intervenção psicomotora e por fim, avaliação final e análise dos resultados obtidos. De uma forma mais pormenorizada são relatados dois estudos de caso, em que o primeiro diz respeito a uma criança sobredotada e o segundo ao grupo da sala Treatment and education of autistic and related communication handicapped children, os quais ilustram a aplicação prática da psicomotricidade, visando a promoção do desenvolvimento de várias áreas, nos domínios motor, comportamental, relacional e afetivo.

O recrutamento e seleção na AutoVision

Mestrado em Gestão de Recursos Humanos

Prevalencia de Trastornos Mentales en consultantes de Centros de Atención Primaria de la Ciudad de Córdoba, Argentina.Prevalence of Mental Disorders among Consultants in Primary Health Care Centers of the City of Córdoba, Argentina

El informe de la Organización Mundial de la Salud (2001), refiere que en un plazo de 20 años los trastornos mentales pasarán a ser la segunda causa dentro de la carga de morbilidad a nivel mundial, y en la actualidad una de cada cuatro personas padece de algún trastorno mental en alguna etapa de su vida. Los estudios realizados en diversos países revelan que una proporción importante de los consultantes de la atención primaria en salud presentan algún tipo de trastornos mentales. Desde esta perspectiva, la atención primaria de la salud ofrece una oportunidad de intervenir en el manejo de los trastornos mentales de forma temprana y eficaz. En Argentina, es limitada la información acerca del registro epidemiológico en salud mental, no contando con estudios abordados desde la Atención Primaria en la provincia de Córdoba. El objetivo general del proyecto es estimar la prevalencia de trastornos mentales entre los consultantes de atención primaria por problemas de salud general. Para ello se propone: Estimar la prevalencia de trastornos mentales en una muestra representativa de consultantes adultos por problemas de salud general, de centros de atención primaria de la ciudad de Córdoba, identificar y describir los tipos de trastornos mentales que presentan estos consultantes adultos de centros de atención primaria y analizar la prevalencia de los trastornos mentales por sexo y edad de la población en estudio. Metodología: el estudio se realizará en consultorios de Atención Primaria de Salud distribuídos en todo el éjido de la ciudad, teniendo en cuenta la representación de las 12 zonas de CPC. La muestra es probabilística, estratificada, polietápica de pacientes que consultan en el primer nivel de atención. Se entrevistarán 1200 pacientes utilizando la versión computorizada del CIDI 3.0, que proporciona diagnóstico de acuerdo a la DSM IV y la CIE-10. La confiabilidad y la validez del instrumento ha sido ampliamente documentada y la traducción de la encuesta al español fue realizada conforme a las recomendaciones de la OMS. El análisis efectuado será de prevalencia de Trastornos Mentales y del Comportamiento (TMC),asociación entre factores sociodemográficos y TCM estimados calculando las razones de disparidad (odds ratio), regresión logística a fin de ajustar los resultados por la posible interacción entre variables, análisis de la asociación de todas las variables con los TMC, análisis univariado de la asociación de cada variable con los TMC, controlando sexo y edad, se construirá un modelo de regresión logística. En todos los casos el nivel de significación será de 0,05. El equipo de trabajo, de cooperación internacional entre profesionales de la UNC y de la Universidad de Chile, y con la participación en colaboración de los profesionales dependientes de la Secretaría de Salud de la municipalidad de Córdoba, representa un avance para trabajar en los centros de salud de esta ciudad, constituyéndose en un avance, cualitativo y cuantitativo de la actividad científica en Atención Primaria en salud mental con abordaje epidemiológico. Se espera contribuir al conocimiento acerca de la prevalencia de los problemas de salud mental de esta población en la ciudad de Córdoba, proporcionando información a los funcionarios y responsables por la gestión de las áreas vinculadas a la salud mental, aportando conocimiento que promueva una temprana identificación de riesgos iniciales en salud mental y conductas de cuidado en la población como potencial de bienestar.Así mismo, se espera sistematizar una experiencia que pueda ser replicada en otros sitios geográficos. Por todo lo anterior, esta propuesta permitirá conocer por primera vez en la ciudad de Córdoba la frecuencia y características de los problemas de salud mental entre consultantes de Atención Primaria, información fundamental para el desarrollo posterior de estrategias que busquen mejorar la detección y el tratamiento de estos problemas. According to the WHO Report (2001), in 20 years, mental health disorders (MHDs) will be the world’s second most frequent cause of morbidity. Primary care offers the opportunity to handle MHDs efficiently at an early stage. In Argentina, the epidemiologic data on mental health (MH) is limited, and there are no records for Córdoba. The aim of this project is to assess the prevalence of MHDs among consultants who resort to primary health centers (PHCCs) in the city of Córdoba for common health problems, by using a representative sample of adult consultants, identifying and describing the types of MHDs evinced, and analysing prevalence by sex and age group under study. Methodology:the study will be carried out in PHCCs located in the municipal area of Córdoba, covering the 12 zones corresponding to the CPCs (municipal branch offices for each zone). A multi-stage stratified random sample of 1200 patients will be interviewed using the program CIDI 3.0 to produce a diagnostic according to DSM IV and CIE-10, a tool with proven reliability and validity.The aspects to be analysed are prevalence of mental and behavior disorders, their association with socio-demographic factors estimated by odds ratios, logistic regression for adjustment of potential interaction among variables, association with all variables, and univariate analysis for association with each variable. Significance level will be 0.05 in all cases. The international teamwork including professionals from the Universities of Córdoba, Chile and the Public Health Department of the Municipality of Córdoba constitutes a qualitative and quantitative step forward in the field of primary health care studies with an epidemiologic approach. This project aims at providing administrators in the MH area with data for the early detection of initial risks in MH and the promotion of prevention habits. This will be the first study conducted in Córdoba, and is aimed at facilitating replication in other geographical areas.

Spectral Analysis Related to Bare-Metal and Drug-Eluting Coronary Stent Implantation

Background: The autonomic nervous system plays a central role in cardiovascular regulation; sympathetic activation occurs during myocardial ischemia. Objective: To assess the spectral analysis of heart rate variability during stent implantation, comparing the types of stent. Methods: This study assessed 61 patients (mean age, 64.0 years; 35 men) with ischemic heart disease and indication for stenting. Stent implantation was performed under Holter monitoring to record the spectral analysis of heart rate variability (Fourier transform), measuring the low-frequency (LF) and high-frequency (HF) components, and the LF/HF ratio before and during the procedure. Results: Bare-metal stent was implanted in 34 patients, while the others received drug-eluting stents. The right coronary artery was approached in 21 patients, the left anterior descending, in 28, and the circumflex, in 9. As compared with the pre-stenting period, all patients showed an increase in LF and HF during stent implantation (658 versus 185 ms2, p = 0.00; 322 versus 121, p = 0.00, respectively), with no change in LF/HF. During stent implantation, LF was 864 ms2 in patients with bare-metal stents, and 398 ms2 in those with drug-eluting stents (p = 0.00). The spectral analysis of heart rate variability showed no association with diabetes mellitus, family history, clinical presentation, beta-blockers, age, and vessel or its segment. Conclusions: Stent implantation resulted in concomitant sympathetic and vagal activations. Diabetes mellitus, use of beta-blockers, and the vessel approached showed no influence on the spectral analysis of heart rate variability. Sympathetic activation was lower during the implantation of drug-eluting stents.

Value of the Qrs-T Angle in Predicting the Induction of Ventricular Tachyarrhythmias in Patients with Chagas Disease

Background:The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown.Objective:Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease.Methods:Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant.Results:Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS.Conclusions:Changes in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.

Echocardiographic Predictors of Worse Outcome After Cardiac Resynchronization Therapy

Abstract Background: Cardiac resynchronization therapy (CRT) is the recommended treatment by leading global guidelines. However, 30%-40% of selected patients are non-responders. Objective: To develop an echocardiographic model to predict cardiac death or transplantation (Tx) 1 year after CRT. Method: Observational, prospective study, with the inclusion of 116 patients, aged 64.89 ± 11.18 years, 69.8% male, 68,1% in NYHA FC III and 31,9% in FC IV, 71.55% with left bundle-branch block, and median ejection fraction (EF) of 29%. Evaluations were made in the pre‑implantation period and 6-12 months after that, and correlated with cardiac mortality/Tx at the end of follow-up. Cox and logistic regression analyses were performed with ROC and Kaplan-Meier curves. The model was internally validated by bootstrapping. Results: There were 29 (25%) deaths/Tx during follow-up of 34.09 ± 17.9 months. Cardiac mortality/Tx was 16.3%. In the multivariate Cox model, EF < 30%, grade III/IV diastolic dysfunction and grade III mitral regurgitation at 6‑12 months were independently related to increased cardiac mortality or Tx, with hazard ratios of 3.1, 4.63 and 7.11, respectively. The area under the ROC curve was 0.78. Conclusion: EF lower than 30%, severe diastolic dysfunction and severe mitral regurgitation indicate poor prognosis 1 year after CRT. The combination of two of those variables indicate the need for other treatment options.

Uma raça cromossômica natural de Tityus bahiensis (Scorpiones-Buthidae)

A natural chromosomal race of Tityus babiensis (Scorpiones Buthidae) is described in the present paper. Five males and seven females received from St. Joaquim, State of S. Paulo, gave the following interesting results: All the spermatogonia of the five males were provided with 9 chromosomes of different sizes. All primary spermatocytes showed at metaphase one independent bivalent of normal shape and a complex group formed by 7 chromosomes which have exchanged parts. Some of the chromosomes associated in the complex group, to Judge by their behavior, were composed of fragments of three different chromosomes, being thus paired with three other members of the compound group. The manner in which all the 7 components of the group have paired with each other showed to be very constant. They gave always origin to a double-cross configuration, the longst branch of which being formed by a long chromosome paired with two components of the group and with a third chromosome that did not belong to the group. The chromosomes of the independent bivalent separate regularly, going to different poles. From the 7 elements of the compound group, 4 go to one pole and 3 to the opposite one. Consequently, secondary spermatocytes with 4 and 5 chromosomes are produced. The females, so far as it can be inferred from the study of the follicular cells of the ovariuterus, have 10 chromosomes. These females are, therefore, considered as being monogametic, that is, as producing eggs with 5 chromosomes. A sex-determining mechanism arose in this manner, the spermatozoa with 5 chromosomes giving origin to females and those with 4 to males. The fact that the sex chromosome is one of the elements taking part in the formation of the group, seems highly interesting to the author. Tetraploid cysts have been occasionally found in the testis. In one individual the chromosomes of the tetraploid primary spermatocytes behaved as expected, forming a group of 14 elements, and two independent pairs or a tetravalent group In another individual, the chromosomes of the tetraploid cells have formed two independent groups of 7, and two independent pairs, as if both chromosomal sets were by their turn entirely independent frcm one another. This fact is certainly not devoid of special interest. The males as well as the females studied in this paper differed in nothing from the typical members of the species. The unique differential character of the new race is found in the umber and behavior of its chromosomes. It is highly remarkable that the occurrences which have transformed the 6 chromosomes normally present in the species into a new set of 9 elements, 7 of which have been profoun- dly altered in their structure, do not show any influence on the morphology of the organism. This fact, together with those found in the salivary-chromosomes races of Drosophila and Sciara. compromises strongly the genetical concept of position effects.

Biologia da Arsenura xanthopus (Walker, 1855) ( Lepidoptera - Adelocephalidae ), praga do «Açoita-Cavalo» (Luehea spp.) e notas sôbre seus inimigos naturais

Biology of Arsenura xanthopus (Walker, 1855) (Lep., Adelocephalidae), a pest of Luehea spp. (Tiliaceae), and notes on its natural enemies. In the beginning of 1950, one of the Authors made some observations about the biology of Arsenura xanthopus (Walker), in Piracicaba, State of S. Paulo, Brazil. From 1951 to 1953, both Authors continued the observations on such an important Adelocephalidae, the caterpillars of which represent a serious pest of Luehea spp. leaves. Actually, in some occasions, the caterpillars can destroy completely the leaves of the trees. The species is efficientely controlled by two natural enemies: an egg parasite (Tetrastichus sp., Hym., Eulophidae) and a fly attacking the last instar caterpillar (Winthemia tricolor (van der Wulp), Dip., Tachinidae). Tetrastichus sp. can destroy 100% of the eggs and the fly, 70 to 100% of the caterpillars. Indeed, facts as such are very interesting because we rarely know of a case of so complete a control of a pest by an insect. A. xanthopus had not yet been mentioned in our literature. Actually neither the systematic bibliography nor the economic one has treated of this species. However, a few other species of Arsenura are already known as living on Luehea spp. According to the Authors' observations, W. tricolor was also unknown by the Brazilian entomological literature. Arsenura xanthopus (Walker, 1855) After giving the sinonimy and a few historical data concerning the species, and its geographical distribution, the Authors discuss its placing in the genus Arsenura Duncan or Rhescyntis Huebner, finishing by considering Arsenura xanthopus as a valid name. The Authors put the species in the family Adelocephalidae, as it has been made by several entomologists. The host plant The species of Tiliaceae plants belonging to the genus Luehea are called "açoita-cavalo" and are well known for the usefulness of their largely utilized wood. The genus comprises exclusively American plants, including about 25 species distributed throughout the Latin America. Luehea divaricata Mart, is the best known species and the most commonly cultivated. Biology of Arsenura xanthopus Our observations show that the species passes by 6 larval stages. Eggs and egg-postures, all the 6 instars of the caterpillars as well as the chrysalid are described. The pupal period is the longest of the cycle, taking from 146 to 256 days. Data on the eclosion and habits of the caterpillars are also presented. A redescription of the adult is also given. Our specimens agreed with BOUVIER's description, except in the dimension between the extremities of the extended wings, which is a little shorter (107 mm according to BOUVlErVs paper against from 80 to 100mm in our individuals). Winthemia tricolor (van der Wulp, 1890) Historical data, geographical distribution and host are first related. W. tricolor had as yet a single known host-; Ar^-senura armida (Cramer). This chapter also contains some observations on the biolcn gy of the fly and on its behaviour when trying to lay eggs on the caterpillars' skin. The female of W. tricolor lays from 1 to 33 eggs on the skin of the last instar caterpillar. The mam region of the body where the eggs are laid are the membranous legs. Eggs are also very numerous oh the ventral surface of the thorax and abdomen. The. preference for such regions is easily cleared up considering the position assumed by the caterpillar when fixed motionless in a branch. In such an occasion, the fly approaches, the victim, puts the ovipositor out and lays the eggs on different parts of the body, mainly on the mentioned regions, which are much more easily reached. The eggs of the fly are firmly attached to the host's skin, being almost impossible to detach them, without having them broken. The minute larvae of the fly enter the body of, the host when it transforms into chrysalid. Chrysalids recentely formed and collected in nature f requentely show a few small larvae walking on its skin and looking for an adequate place to get into the body. A few larvae die by remaining in the skin of the caterpillar which is pushed away to some distance by the active movements of the chrysalid recentely formed. From 1 to 10 larvae completely grown may emerge from the attacked chrysalid about 8 days after their penetrating into the caterpillars' body and soon begin to look for an adequate substratum where they can transform themselves into pupae. In natural conditions, the metamorphosis occurs in the soil. The flies appear within 15 days. Tetrastichus sp. This microhymenoptera is economically the most interesting parasite, being commonly able to destroy the whole pos^ ture of the moth. Indeed, some days after the beginning of the infestation of the trees, it is almost impossible to obtain postures completely free of parasites. The active wasp introduces the ovipositor into the egg of the moth, laying its egg inside, from 80 to 120 seconds after having introduced it. A single adult wasp emerges from each egg. Sarcophaga lambens Wiedemann, 1830 During the observations carried out, the Authors obtained 10 flies from a chysalid that were recognized as belonging to the species above. S. lambens is a widely distributed Sarcophagidae, having a long list of hosts. It is commonly obtained from weak or died invertebrates, having no importance as one of their natural enemies. Sinonimy, list of hosts and distribution are presented in this paper. Control of Arsenura xanthopus A test has been carefully made in the laboratory just to find out the best insecticide for controlling A. xanthopus caterpillars. Four different products were experimented (DDT, Pa-rathion, BHC and Fenatox), the best results having been obtained with DDT at 0,25%. However, the Authors believe in spite of the initial damages of the trees, that the application of an insecticide may be harmful by destroying the natural agents of control. A biological desiquilibrium may in this way take place. The introduction of the parasites studied (Tetrastichus sp. and Winthemia tricolor) seems to be the most desirable measure to fight A. xanthopus.

Adubação e irrigação de café: adubação combinada com irrigação no primeiro ano da instalação das covas

This paper deals with different types of fertilizer applications in coffee hill in the moment of transfering the plants to the field. During the first year, irrigation was applied in the dry season. After one year, the following characters were analised: plant height; plant diameter; number of productive branches; lenght and number of nodes in the first branch of the plant. The results obtained can be summarized as follows: the irrigation employed did not affect the treatments and mineral fertilizers combined with organic fertilizer were better than the others treatments used for comparisons.

Estudos sobre a alimentação mineral do cafeeiro: XII. efeito da adubação na composição mineral das fôlhas

Leaf samples from coffee plants under three different fertilizations, namely NPK, NP and PK, were collected for chemical analysis. It was found that the contents of N, K, Ca, Mg and S in the first, second, third and fourth pair of leaves were the same from the statistical point of view. On the onder hand, there was a significant effect of the position of the leaf in the branch on the P content, which was higher in the first pair. With the exception of the P level ,the four pairs of leaves are chemically uniform. Nevertheless it is not considered as convenient to mix all kinds of leaves into one sample, since the composition may vary a great deal when sampling is done some other time, such as the period of fruit growing. It is recommended therefore that either the third or the fourth pair leaves should be collected for routine work in foliar diagnosis.

Histology of the liver of Oligosarcus jenynsii (Ostariophysi, Characidae) from Los Padres Lake, Argentina

The liver is an organ notable for its sensitivity to a great variety of environmental factors. It is composed of a parenchyma divided into irregular lobules by the exocrine pancreas or hepatopancreas; the pancreatic cells are arranged around a branch of the portal vein. The hepatocytes are radially arranged in cords around a central sinusoid. The liver histomorphology and the organization of exocrine pancreatic tissue of O. jenynsii (Günther, 1864) is similar to the acinar morphology of many teleosts, including freshwater and marine species. The aim of the present work was to carry out the histological analysis of the liver of Oligosarcus jenynsii, one of the most common species inhabiting Los Padres Lake (Buenos Aires Province, Argentina).