[Influence of the albumin fraction in the plasma oncotic pressure (author's transl)]. / Influencia de la fracción albúmina en la presión oncótica plasmática.

This work analyzes the influence which albumin fraction exerts upon plasma oncotic pressure. With this objective three different groups were studied, each one of which was composed of subjects with identical total proteinemia and variable albuminemia. The first group: nine subjects with 6.2 g/100 ml proteinemia and albumin values between 3.2 and 3.8 g/100 ml; the second group: seven healthy subjects with 6.4 g/100 ml proteinemia and the level of albumina between 3 and 4 g/100 ml; the third group: subjects with proteinemia at 6.6 g/100 ml and extreme values of albumin between 3.1 and 4.3 g/100 ml. Plasma oncotic pressure was determined by means of an electronic osmometer, according to the described technique. With a proteinemia constant at 6.2 g/100 ml, a 0.6 percent fluctuation of the albumin concentration induced a variation in the plasma oncotic pressure of up to 20.4 per cent. In cases of proteinemia remaining constant at 6.4 g/100 ml, the oscillation of albumin levels between 3 and 4 g/100 ml represented a change in the plasmatic oncotic pressure of 32.58 per cent. In the third group, the influence of the albuminemia was lesser (23.1 per cent variability in the plasma oncotic pressure, with an oscillation of 1.2 g/100 ml in albuminemia). The existence of variable values of plasma oncotic pressure corresponding to cases with identical proteinemia and albuminemia, lead us to consider the powerful influence exerted upon the plasma oncotic pressure by other factors which affect the mass-structure and the electrical charges of proteins.

[Iatrogenic gastrointestinal hemorrhages. A review of 108 cases (author's transl)]. / Hemorragias digestivas yatrógenas. Consideraciones en torno a 108 casos.

Macroscopic gastrointestinal hemorrhages caused by the consumption of oral drugs are relatively scarce among patients receiving antirheumatic treatment. On the other hand, in a high percentage of all cases of digestive bleeding, antirheumatic drugs were administered shortly beforehand. A review of 216 cases with hematemesis and/or melena are presented. In 50 percent of the patients there was evidence of previous administration of potentially ulcerogenic drugs capable of causing hemorrhages in the digestive tract. Salicylates predominated among the compounds that were considered to be responsible for hemorrhages (salicylates, corticosteroids, reserpine, and other antirheumatic products). The mechanisms involved in producing iatrogenic hemorrhages were examined and the drugs were classified as precipitating and directly ulcerogenic compounds. Precipitating drugs were those which were able to reactivate a preexisting lesion (reserpine, glucocorticoids, phenylbutazone, etc.). The ulcerogenic drugs included those products that could provoke a lesion of previously unimpaired digestive mucosa (salicylates).

[Investigation of the hypoosmolal syndrome in carcinomas of the lung (author's transl)]. / Investigación del síndrome hipoosmolal en el carcinoma de pulmón.

A study was performed on 30 patients diagnosed antomopathologically for malignant neoplasia of the lung (epidermoid carcinomas, adenocarcinomas, oat-cell carcinomas, and neoplasias which could not be definitely classified). The following parameters for blood and urine were determined: osmolality, sodium, potassium, urea, and creatinine. Osmotic free water, creatinine, sodium, and potassium clearances were also calculated, as well as the plasma osmolality/urinary osmolality ratio. The basic aim of our study was to investigate for the presence of disturbances in the metabolism of water and alterations in plasmatic and urinary osmolality in this type of tumor. These could appear as complete inadequate ADH secretion syndromes as discovered by Bartter and Schwartz or as incomplete syndromes (hypoosmolality and/or hyponatremia). Among the more significant results was the tendency toward oliguira seen in 44% of the patients and the high incidence of plasmatic hypoosmolality (31%). In three patients plasmatic hypoosmolality and hyponatremia were concommitant in repeated observations. A complete inadequate ADH secretion syndrome was discovered in another patient with an oat-cell carcinoma. He presented plasmatic hypoosmolality, hyponatremia, relative urinary hypertonia, and oliguria but not renal, suprarenal, or hepatic pathology.

[Direct method for osmotic pressure measurement (author's transl)]. / Técnica de medición directa de la presión oncótica.

A new dynamic method to measure osmotic pressure was presented. The method is easy and with only a 1.8% degree of error. All determinations were done with an osmometer, equipped with three small chambers of methyl metacrilate and dialyser membranes. The central area had two capillaries: one for measuring and the other for changing dynamic pressure. The data from different albumin concentrations were satisfactory, and they agreed with published results from others. The present results indicate that osmotic pressure is an exponential function of albumin concentration.