Multivariate methods in research.

Univariate methods are very helpful when utilized appropriately within the research analysis. However, there are many occasions in which only multivariate methods will satisfy an optimal assessment. In this case, multivariate methods will permit the researcher to incorporate many variables within a single research analysis. This work reviews the use of multivariate methods and how to apply them in clinical medicine.

The impact of low-residue enteral feeding on the healing of colonic anastomoses.

This study was carried out with the aim of comparing colonic anastomosis cicatrization in rats fed either standard rat chow or a low-residue enteral diet. Energy intake, the evolution of body weight, fecal weight, macroscopic and microscopic evaluation of the anastomoses, anastomotic bursting pressure, and collagen concentration in the anastomotic tissue were all evaluated. Anastomotic complications were more common among the animals fed standard rat chow, and cicatrization was more inflammatory than in the rats given a low-residue enteral diet. Although the latter was more effective in preventing anastomotic complications, it resulted in a lower gain in collagen and hence a diminished resistance to the increase in intraluminal pressure associated with the administration of such diets. Colonic contents, including the fecal bolus and bacteria, may be held responsible for the increased number of complications, the augmentation of collagen content, and the improvement in the resistance to intraluminal pressure.

[The recording of renal cortical blood flow by laser Doppler flowmetry]. / Registro del flujo sanguíneo cortical renal mediante flujometría láser-Doppler.

Several techniques are available for measuring the microcirculation. The results, however, cannot be extrapolated due to the different, intricate microvasculature of each organ system. We measured the renal cortical blood flow using laser Doppler flowmetry. This flowmeter permits blood flow measurements of very small areas of tissue. Precise information from selected areas, such as the renal cortex, can thus be obtained. The results are expressed in perfusion units (PU).

[Low-residue diets supplemented with fermentable fiber. Effect on experimental colonic anastomosis]. / Dietas de bajo residuo suplementadas con fibra fermentable. Efecto sobre las anastomosis cólicas experimentales.

Presentation of an experimental study comparing the scarring of colic anastomoses performed in Wistar rats fed with three different types of diet: a standard laboratory diet, an enteral low-residue diet and a low-residue diet supplemented with fermentable fibre in short chain fatty acids (pectin). Scarring in the group fed with the standard laboratory diet showed greater anastomotic complications, and the microscopic appearance was more inflamed. The administration of low-residue diets reduced the level of complications, but also reduced the concentration of collagen and the parietal rupture tension. The addition of pectin to a low-residue diet maintained the complications at a low level, and also significantly increased the pressure parameters and the collagen concentration.

[Antiulcerogenic properties of bran rice oil in rats]. / Estudio de las propiedades antiulcógenas del aceite de salvado de arroz (ASA) en la rata.

A study was made of the effect of rice chaff oil (ASA) on gastroduodenal ulcer (UGD) induced by different techniques: cysteaminium chloride, indomethacin, artificial gastric juices and stress (acidity, histamine, pepsin and volume of gastric juice were evaluated). For each technique the same protocol was followed: four days before the experiment 20 Wistar rats (180-220 g) were divided into a control group (0.2 ml/day of saline solution per os) and a treated group (0.2 ml/day of oral rice chaff oil). After quantitation of the ulcers and statistical analysis of the data, the ulcer index was found to be smaller in the treated group than in controls, both for stress ulcers (p less than 0.01) and for those induced by indomethacin (p less than 0.001) and artificial gastric juice (p less than 0.001). As for the cysteaminium chloride technique, an evaluation was made of the ulcer per se and the inflammatory halo; in both cases there were significant differences (p less than 0.05 and p less than 0.01 respectively) between the treated group and controls. No significant differences were found on comparing the values off histamine, pepsin and the volume of gastric juices, but there were differences in hydrogen ion concentration (p less than 0.05). An analysis is made of the physiologic aspects studied in each technique, emphasizing the possible implication of prostaglandins (PG) and alpha-tocopherol after treatment with rice chaff oil.