Hyperactive ENaC identifies hypertensive individuals amenable to amiloride therapy.

Pathophysiological features of both primary aldosteronism and pseudohyperaldosteronism are hyperactive amiloride-sensitive epithelial Na(+) channels (ENaC) and refractory hypertension. Peripheral blood lymphocytes express ENaC, which functions and is regulated similarly to ENaC expressed by renal principal cells. Thus it was hypothesized that individuals with either of these hypertensive etiologies could be identified by assessment of the function and regulation of peripheral blood lymphocyte ENaC, by whole cell patch clamp. We also tested the hypothesis that specific inhibition of hyperactive ENaC with amiloride could ameliorate the hypertension. To test these hypotheses, we solicited blood samples from normotensive, controlled hypertensive, and refractory hypertensive individuals. Lymphocytes were examined electrophysiologically to determine whether ENaC was hyperactive. All positive findings were from refractory hypertensive individuals. Nine refractory hypertensive patients had amiloride added to their hypertensive therapy. Amiloride normalized the blood pressure of four subjects. These individuals all had hyperactive ENaC. Amiloride had no effect on individuals with normal ENaC. These findings suggest that whole-cell patch clamp of peripheral blood lymphocytes can be used to identify accurately and rapidly hypertensive individuals who will respond to amiloride therapy.

Cerebral microgyria, thalamic cell size and auditory temporal processing in male and female rats.

Induction of microgyria by freezing injury to the developing somatosensory cortex of neonatal rats causes a defect in fast auditory processing in males, but not in females. It was speculated that early damage to the cortex has sexually dimorphic cascading effects on other brain regions mediating auditory processing, which can lead to the observed behavioral deficits. In the current series of experiments, bilateral microgyri were induced by placement of a freezing probe on the skulls of newborn male and female rats, and these animals were tested in adulthood for auditory temporal processing. Control animals received sham surgery. The brains from these animals were embedded in celloidin, cut in the coronal plane and the following morphometric measures assessed: microgyric volume, medial geniculate nucleus (MGN) volume, cell number, and cell size, and, as a control, dorsal lateral geniculate nucleus (dLGN) volume, cell number and cell size. There were no sex differences in the cortical pathology of lesioned animals. However, microgyric males had more small and fewer large neurons in the MGN than their sham-operated counterparts, whereas there was no difference between lesioned and sham-operated females. There was no effect on dLGN cell size distribution in either sex. Microgyric males were significantly impaired in fast auditory temporal processing when compared to control males, whereas lesioned females exhibited no behavioral deficits. These results suggest that early injury to the cerebral cortex may have different effects on specific thalamic nuclei in males and females, with corresponding differences in behavioral effects.

High resolution real-time ultrasonography in the localization of the undescended testis.

In a prospective study ultrasound was compared to palpation in 41 instances in which a testis was not present in the scrotum. A testis was palpable in 20 of these instances and not palpated in 21. Of 20 palpable undescended testes 14 (70 per cent) were identified by ultrasound. Of the 21 instances in which a testis was not palpated 3 intra-abdominal and 5 inguinal testes were identified at exploration. One of these organs (an inguinal testis) was identified by ultrasound. Two false positive sonograms in which a gubernacular structure mimicked an undescended testis occurred. Sonography cannot satisfactorily stand alone as a screening modality in the management of the undescended testis.

Duplex Doppler: identification of cavernous transformation of the portal vein.

Three cases of cavernous transformation of the portal vein are presented, which emphasize the value of duplex Doppler sonography in the recognition of abnormal vascular structures. In all three cases, cavernous transformation was unsuspected; in two, the initial sonographic or CT examinations were interpreted incorrectly. These cases suggest that the combination of characteristic pulsed-Doppler waveforms and the real-time appearance of cavernous transformation is virtually diagnostic.

The junctional parenchymal defect: a sonographic variant of renal anatomy.

A triangular echogenic area in the upper pole renal parenchyma can be identified at times during routine sonography of the right kidney. Thirty such cases are presented. Occasionally similar echogenic defects in the parenchyma can be seen posteriorly in the lower pole and in the left kidney. These defects in the parenchyma result from normal extensions of the renal sinus of kidneys that have a distinct division of their upper and lower poles. This is due to partial fusion of two embryonic parenchymatous masses called renunculi. The defects in the parenchyma occur at the junction of the renunculi; hence we have termed them junctional parenchymal defects. In order to differentiate them from pathologic conditions, one must identify their characteristic location and demonstrate continuity with the renal sinus.

Thoracic alterations after cardiac surgery.

A series of 92 adult patients undergoing elective cardiac surgery was reviewed to distinguish routine postoperative radiographic alterations from signs of clinically significant complications. Two postoperative complications required decisive clinical intervention: mediastinal hemorrhage (7% of cases) and sternal wound infections (3% of cases). Mediastinal hemorrhage was most often diagnosed by excessive bloody mediastinal tube drainage alone, although progressive mediastinal widening and pleural or apical extrapleural hematomas provided corroborating or, rarely, the sole evidence of mediastinal hemorrhage. Sternal wound infections were most often diagnosed clinically, but increasing pre- and retrosternal gas collections provided radiographic confirmation. Atelectasis was the most common postoperative finding. There were many abnormal gas and soft-tissue collections posteroperatively that were notable for their lack of clinical importance. Serial postoperative films were necessary to demonstrate the progression of radiographic findings which indicate the two important postoperative complications.

Large subarticular cysts (geodes) adjacent to the knee-joint in rheumatoid arthritis.

Two patients with rheumatoid arthritis are described, who developed very large bone cysts or geodes adjacent to the knee-joint. The existence of cysts adjacent to joints involved by rheumatoid arthritis is well recognised, but the occurrence of very large cysts is unusual and may present diagnostic difficulties. Possible aetiological factors are discussed.