Zoo-heleoplankton structure in three artificial ponds of North-eastern Argentina.

The aim of the present study was to compare the abundance and species richness of zoo-heleoplankton bigger than 53 microm in an annual cycle under similar climate conditions in three artificial ponds, in order to observe the changes during an annual cycle. Samples were taken monthly from June 1993 to July 1994 in Corrientes, Argentina. The first pond (A) was covered an 80% by Eichhornia crassipes (Mart.), the second one (B) with bloom of Microcystis aeruginosa (Kurtzing) and the last one (C) with organic matter deposited in the bottom. The water was more acidic at pond A, and the water at pond B contained more dissolved oxygen concentration than the water at the other two ponds. The zoo-heleoplankton densities varied between 20-1728 ind.l(-1) at pond A, 42-4082 ind.l(-1) at pond B and 148-2447 ind.l(-1) at pond C. The maximum zoo-heleoplankton abundance was found in the pond with cyanobacteria bloom during Autumn 1994 and the minimum abundance was found in the one with a predominance of E. crassipes. The rank of species richness was pond A > pond B > pond C. Rotifera was the most abundant group in pond A whereas the larval stages of Copepoda were abundant in the other two ponds. Anuraeopsis navicula Rousselt 1910 was the dominant population in the pond with macrophytes prevalence. Brachionus calyciflorus Pallas 1776 and larval stage of Copepoda had variable proportions in the pond with cyanobacteria bloom. Thermocyclops decipiens (Kiefer 1929) was present during the annual cycle only in the pond with organic matter deposited in the bottom. The succession of taxa was observed in the pond with coverage of aquatic macrophytes and with cyanobacteria bloom. Differences in species richness and low similarity in zoo-heleoplankton between ponds were determined by differences in the quality of the water in relation to the presence of macrophytes, cyanobacteria, organic matter deposited in the bottom and fish predation. Multiple regression analysis (stepwise) revealed that water transparency, dissolved oxygen and conductivity were the environmental variables that explained more than 42% of variability in the abundance of the dominant species.

[Heart rupture in acute myocardial infarct]. / La rottura cardiaca nell'infarto miocardico acuto.

24 cases of cardiac rupture (CR) (12%) were found in 200 necropsies of patients who died from acute myocardial infarction (AMI). Examination of the various factors that may affect the onset of this complication showed that age, sex, the site of AMI, the presence of coronary thrombosis, the association of persistent arterial hypertension, diabetes mellitus or previous angina syndrome and anticoagulant and corticosteroid treatment are insignificant. On the other hand, previous myocardial infarction would appear to reduce incidence considerably. CR was much more frequent in the first 3-4 days after onset of AMI and never occurred more than 21 days after. An important premonitory sign is persistent precordial pain in the absence of pericardial friction. Cardiokinetic therapy was used in 70% of the CR cases examined here. Over the past decade, the frequency of CR secondary to AMI has risen appreciably and it is hypothesised that this increase may have been influenced by the readiness with which cardiokinetics are employed now during AMI, often in very high doses. Particularly in the case of patients at high CR risk, it is considered that cardiokinetic therapy should only be employed in cases of clear cardiac insufficiency, in small, fragmented doses and after diuretics and vasodilators have proved ineffective. Such patients can also usefully be transferred to specialist wards for emergency surgery or preventive infarctectomy.

[Electrocardiographic changes in acute carbon monoxide poisoning]. / Alterazioni elettrocardiografiche in corso di intossicazione acuta da monossido di carbonio.

Various electrocardiographic alterations (variations in the repolarisation phase, disturbed conduction, arrhythmias) have been reported in acute carbon monoxide poisoning. In the 44 cases of this poisoning examined, electrocardiographic alterations are also considered in relation to the degree of poisoning (expressed as plasmatic levels of carboxyhaemoglobin-HbCO). In 68% of these cases alterations were presented by signs of subepicardiac or subendocardiac damage. Attacks of atrial fibrillation, premature beats and episodes of sinusal tachycardia were also observed. Almost all these electrocardiographic alterations were quickly reversible. It is concluded that there is no correlation between HbCO levels and electrocardiographic alterations (that were in fact more frequent in the slight poisoning cases).

[Epulis. A clinical study of 80 cases]. / Epulide. Studio clinico su 80 casi.

Epulis cases observed over an eight-year period are examined. Results are assessed and compared with reported statistics.

[Lesions of the inferior alveolar nerve]. / Lesioni nervose a carico del nervo alveolare inferiore.

All possible forms of inferior alveolar nerve injury are examined with a report on several personal cases and their medicolegal implications.

Zoo-heleoplankton structure in three artificial ponds of North-eastern Argentina

The aim of the present study was to compare the abundance and species richness of zoo-heleoplankton bigger than 53 µm in an annual cycle under similar climate conditions in three artificial ponds, in order to observe the changes during an annual cycle. Samples were taken monthly from June 1993 to July 1994 in Corrientes, Argentina. The first pond (A) was covered an 80% by Eichhornia crassipes (Mart.), the second one (B) with bloom of Microcystis aeruginosa (Kurtzing) and the last one (C) with organic matter deposited in the bottom. The water was more acidic at pond A, and the water at pond B contained more dissolved oxygen concentration than the water at the other two ponds. The zoo-heleoplankton densities varied between 20-1728 ind.l-1 at pond A, 42-4082 ind.l-1 at pond B and 148-2447 ind.l-1 at pond C. The maximum zoo-heleoplankton abundance was found in the pond with cyanobacteria bloom during Autumn 1994 and the minimum abundance was found in the one with a predominance of E. crassipes. The rank of species richness was pond A > pond B > pond C. Rotifera was the most abundant group in pond A whereas the larval stages of Copepoda were abundant in the other two ponds. Anuraeopsis navicula Rousselt 1910 was the dominant population in the pond with macrophytes prevalence. Brachionus calyciflorus Pallas 1776 and larval stage of Copepoda had variable proportions in the pond with cyanobacteria bloom. Thermocyclops decipiens (Kiefer 1929) was present during the annual cycle only in the pond with organic matter deposited in the bottom. The succession of taxa was observed in the pond with coverage of aquatic macrophytes and with cyanobacteria bloom. Differences in species richness and low similarity in zoo-heleoplankton between ponds were determined by differences in the quality of the water in relation to the presence of macrophytes, cyanobacteria, organic matter deposited in the bottom and fish predation. Multiple regression analysis (stepwise) revealed that water transparency, dissolved oxygen and conductivity were the environmental variables that explained more than 42% of variability in the abundance of the dominant species. Rev. Biol. Trop. 56 (3): 1135-1147. Epub 2008 September 30.

La finalidad del presente estudio fue comparar la abundancia y riqueza de especies del zoo-heleoplancton mayor de 53 µm, en un ciclo anual bajo condiciones climáticas similares en tres estanques artificiales, con el propósito de observar los cambios durante un ciclo anual. Las muestras fueron tomadas mensualmente desde junio de 1993 hasta julio de 1994 en Corrientes, Argentina. El primer estanque (A) estuvo cubierto un 80% por E. crassipes, el segundo estanque (B) con floraciones de M. aeruginosa y el tercer estanque (C) con materia orgánica depositada en el fondo. El agua fue más ácida en el estanque A y tuvo más concentración de oxígeno disuelto en el B. La densidad del zoo-heleoplancton fue variable entre 20-1728 ind.l-1 en el estanque A, 42-4082 ind.l-1 en el estanque B y 148-2447 ind.l-1 en el estanque C. El rango de la riqueza de especies fue estanque A> estanque B> estanque C. La máxima abundancia del zoo-heleoplancton se encontró en el estanque con floraciones de cianobacterias y la mínima entre macrófitas de E. crassipes. Rotifera fue el grupo más abundante en el estanque con presencia de macrófitas. Los estadios larvales de Copepoda fueron abundantes en los estanques con materia orgánica depositada en el fondo y con dominancia de cianobacterias. A. navicula fue la población dominante en el agua libre del estanque con predominio de macrófitas. B. calyciflorus y estadios larvales de Copepoda tuvieron proporciones variables en el estanque con cianobacterias. T. decipiens fue la única población presente en el estanque con materia orgánica depositada en el fondo. Se observó un patrón de sucesión de los taxa en el estanque con importante cobertura de macrófitas acuáticas y con floraciones de cianobacterias. Las diferencias en la riqueza de especies y la baja similitud del zoo-heleoplancton entre los estanques estuvieron determinadas por la calidad del agua en relación con la presencia de macrófitas, cianobacterias, materia orgánica depositada en el fondo y peces. El análisis de regresión múltiple (stepwise) reveló que la transparencia del agua, el oxígeno disuelto y la conductividad fueron las variables ambientales que explican más de 42% de variabilidad en la abundancia de las especies dominantes.