Habituation of the cold pressor response in normo- and hypertensive human subjects

The changes in cardiovascular response to repeated cold-pressor test were studied in young normotensive and in young hypertensive subjects. The cold stimulus consisted of immersing one foot in cold water (4 degrees C) for 60 s. Non-invasive methods were used to record the cardiovascular responses: blood flow of the calf was measured using venous occlusion plethysmography, arterial blood pressure with sphygmomanometery, heart rate with electrocardiography. The vascular conductance level in the calf was higher in hypertensive subjects than in normotensives. The difference remained throughout the series of 6 daily experiments. In both hypertensive and normotensive groups of subjects some individuals responded to the cold stimulus with vasodilatation in the calf muscles, others with vasoconstriction. In the hypertensives blood flow increased more and habituation was only transient with a strong tendency for the vasodilatory response to recover, while in normotensives habituation was rapid and complete. Vasoconstrictor responses showed no signs of reduction. The blood pressure increases were larger in hypertensives and remained unaltered within the period of repeated tests (6 days). There was not significant difference between the heart rate changes in the two groups of subjects. It is concluded that the vasculature of the calf shows lower tone and is more labile during the early stage of hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Positive TTF-1 Expression in Malignant Mesothelioma: A Case Report

BACKGROUND

The histopathological diagnosis of malignant mesothelioma is based mainly on the immunohistological profile of the neoplasia, using different immunohistochemical markers to distinguish between a malignant mesothelioma and a carcinoma.

CASE REPORT

A female patient presented with a right paravertebral rapidly growing tumor and severe pain. Based on the immunohistochemical findings, we present the first case of a malignant mesothelioma with immunohistochemical expression of thyroid transcription factor-1.

CONCLUSIONS

The detection of a positive reaction for thyroid transcription factor-1 in the tumor cells may not exclude a malignant mesothelioma.