Morphometry: assessing direct and indirect methods of measuring the diameters of tubular structures / Morfometría: evaluación de métodos directos e indirectos para medir los diámetros de las estructuras tubulares

SUMMARY: Knowledge of the diameter of a structure or particle is required for stereological calculations. However, there is no consensus on the methodology for its measurement. This study aims to assess the differences between direct and indirect methods of measuring diameter. It is hypothesised that kidneys were removed, fixed, processed, sectioned, and stained. The stained slides were imaged using a digital microscope. The images were processed using the ImageJ software. The diameters of the renal glomeruli and collecting tubules were measured using direct and indirect methods. The measured diameters were analysed using the SPSS software v20. The differences between the measurements were assessed using a Z-test and test of association, and P < 0.05 was considered significant. No significant differences were observed between the diameters of the glomeruli (P = 0.82) and proximal (P = 0.86) and distal (P = 0.55) convoluted tubules as measured via direct and indirect methods. There was a strong positive correlation between the diameters of glomeruli (P = 0.97) and proximal (P = 0.82) and distal (P = 0.93) convoluted tubules measured using the two methods, both of which are convenient, accurate and suitable. The P-values based on these measurements were more than 0.05. Therefore, the study hypothesis was rejected. There was no significant difference between the direct and indirect methods of measuring diameter, and the null hypothesis was rejected; thus, both methods can be applied either independently or jointly.

RESUMEN: Se requiere el conocimiento del diámetro de una estructura o partícula para los cálculos estereológicos. Sin embargo, no existe consenso sobre la metodología para su medición. Este estudio tuvo como objetivo evaluar las diferencias entre los métodos directos e indirectos de medición del diámetro de una estructura. Riñones de ratas Wistar fueron extirpados, fijados, procesados y seccionados, y luego se tiñeron con HE. Se tomaron imágenes de las muestras teñidas usando un microscopio digital. Las imágenes fueron procesadas utilizando el software ImageJ. Los diámetros de los glomérulos renales y túbulos colectores se midieron por métodos directos e indirectos. Los diámetros medidos se analizaron utilizando el software SPSS v20. Las diferencias entre las medidas se evaluaron mediante una prueba Z y una prueba de asociación, y se consideró significativa P < 0,05. No se observaron diferencias significativas entre los diámetros de los glomérulos (P = 0,82) y túbulos contorneados proximales (P = 0,86) y distales (P = 0,55) medidos mediante métodos directos e indirectos. Hubo una fuerte correlación positiva entre los diámetros de los glomérulos (P = 0,97) y los túbulos contorneados proximales (P = 0,82) y distales (P = 0,93) medidos con los dos métodos, ambos convenientes, precisos y adecuados. Los valores P basados en estas mediciones fueron superiores a 0,05. Por lo tanto, se rechazó la hipótesis del estudio. No hubo diferencia significativa entre los métodos directo e indirecto de medición del diámetro, y se rechazó la hipótesis nula; por lo tanto, ambos métodos se pueden aplicar de forma independiente o conjunta.

Histological and immunohistochemical study on the changes induced by contraceptive pills in the female rabbit's kidney

The mechanism for the development of overt hypertension due to the oral contraception ingestion remains unclear. Experimental evidence favors a role for the renin-angiotensin system. The present study focuses on evaluating the effect of two different contraceptive pills including combined pills [estrogen and progesterone] and mini pills [progesterone only] on the kidney of female rabbit. After three month of daily oral administration of these contraceptive pills the animals were sacrificed. The excised kidneys were dissected, processed and stained with H and E, PAS and Masson's trichrome and anti-angiotensin II immunohistochemical stains. This was followed by morphometric measurements and statistical study. This study revealed that contraceptive pills administration specially the combined one caused marked alterations in the form of damaged kidney tubules with cell swelling and loss of brush border and enlarged glomeruli with hypercellularity. Also, a statistically significant increase in collagenous content peritubular and peri and intraglomerular was observed. There was also a statistically significant increase in the anti-Angiotensin II immunoreactivity in renal tubules as well as intra-glomerular and in the interstitial cells. All these changes were less marked after mini pill treatment. Progesterone only pills could be safer on the kidney as a contraceptive mean when compared to combined pills

Alteraciones en las características morfométricas del riñón de ratas albinas machos provocadas por la ingestión crónica de etanol desde la adolescencia / Alterations in the morphometric features of kidney of male albino rats provoked by chronic ingestion of ethanol from the adolescence

En el presente trabajo se pretendió determinar las variaciones que sobre las características morfométricas del riñón provoca la ingestión crónica de etanol en ratas adolescentes, para lo cual se utilizaron 42 ratas albinas machos de 30 días de nacidas con las cuales se conformaron dos grupos de 21 animales cada uno y con tiempos de tratamiento de tres y cinco meses y con estos, dos subgrupos: experimental y control. A las ratas experimentales se les suministró etanol a dosis de 5 g/kg de peso corporal mediante cánula intraesofágica. A las controles se les administró agua en lugar de etanol, en iguales condiciones. Se emplearon cortes histológicos coloreados con técnica PAS y se estudiaron las porciones contorneadas de los túbulos proximales y distales. Se calculó el área de sección transversal tubular y se midieron los volúmenes nucleares de las células de ambos túbulos. Se comprobó que las ratas experimentales mostraron volúmenes nucleares menores que las controles. El grupo experimental mostró valores de áreas de sección transversal de los túbulos renales mayores que los controles, siendo estos valores superiores en los túbulos proximales en las ratas de cinco meses, y los distales en las ratas de tres meses. Se concluyó que en la muestra estudiada el alcoholismo crónico iniciado en la adolescencia provocó variaciones morfométricas en los túbulos proximales y distales del riñón

Present paper allowed us to determine the variations exerted by the chronic ingestion of ethanol from the adolescence on the kidney morphometric features in 42 male albino rats of 30 days born divided into two groups of 21 animal each and with the treatment times of three and five months and with these 42 animals into two subgroups: one of experimental type and other as control. The experimental rats received ethanol at 5 g/kg doses according to the body weight using an intraesophageal cannula. The control ones received water instead of ethanol in similar conditions. We used histological sections stained with PAS technique to study the outlined portions of the proximal and distal tubules. The tubular transversal section area was estimated measuring the nuclear volumes of cells in both tubules. It was demonstrated that the experimental rats showed higher values of the transversal section of renal tubules higher than the control ones, where these values were superior in proximal tubules in the five months old rats and the distal ones in the three months old. We conclude that in study sample the chronic alcoholism started during adolescence provoked morphometric variations in proximal and distal tubules of kidney