On the genesis of heartburn

The primary function of the lower esophageal sphincter is to prevent reflux of acid gastric contents, and heartburn is the cardinal symptom of its failure. Standard meals of protein, carbohydrate, and fat have been shown to have significant effects on lower esophageal sphincter pressure. Most patients with heartburn relate their symptoms to certain foods, few of which contain pure protein, carbohydrate, or fat. We have studied the effects of some of these foods on the lower esophageal sphincter. Whole and nonfat milk were also studied because of their frequent use in heartburn therapy. Pressure in the lower esophageal sphincter was recorded continously in normal subjects using an infused open-tipped system. Test meals consisted of 240-cc quantities of water (control), whole milk, nonfat milk, orange juice, a mixture of tomato paste and water, and dilutions of chocolate syrup. Slight, but significant (P<0.05) decreases in lower esophageal sphincter pressure occurred after whole milk ingestion. By contrast, nonfat milk produced significant (P<0.05) increases in pressure. Orange juice and tomato both caused only transient decreases in pressure with gradual return to the baseline and considerable pressure variation and secondary contractions. Chocolate syrup (1.2% fat) produced immediate and sustained decreases in sphincter pressure (P<0.005) associated with symptomatic reflux in some subjects.     

Subpleural micronodules in diffuse infiltrative lung diseases: evaluation with thin-section CT scans

Thin-section computed tomography (CT) was performed in 244 patients with infiltrative lung diseases and 29 healthy control subjects to evaluate the frequency, profusion, and diagnostic value of subpleural parenchymal micronodules. These areas of increased attenuation (less than 7 mm in diameter) were analyzed in four groups: coal miners with chest radiographic findings of coal worker's pneumoconiosis (n = 61), coal miners with no radiographic evidence of pneumoconiosis (n = 73), patients with nonoccupational chronic infiltrative lung disease (n = 110), and healthy adults (n = 29). Subpleural parenchymal micronodules were observed with high frequency in pulmonary lymphangitic carcinomatosis, coal worker's pneumoconiosis, and sarcoidosis but were also seen in 14% of control subjects. Predominant sites of lesions were the posterior subpleural areas in the upper lobes. Subpleural parenchymal micronodules have no diagnostic value when observed as an isolated CT finding but may suggest that diagnosis of pneumoconiosis, sarcoidosis, or pulmonary lymphangitic carcinomatosis when observed in association with mild parenchymal lesions.     

Effect of DOCA-salt on angiotensin dependency and surgical reversal of hypertension in two-kidney, one clip renal hypertensive rats

The development of hypertension in two-kidney, one clip renal hypertensive rats (2K, 1C RHR) was not altered by treatment with DOCA and saline solution as drinking fluid for two months of observation. However, the administration of DOCA and salt suppressed plasma renin activity (PRA), the renal renin content (RRC) of the clipped kidney and the response to a single oral dose of captopril (10 mg/kg). The weight of the contralateral kidney was increased by the administration of DOCA-salt, while that of the ischaemic kidney was not changed. The withdrawal of DOCA-salt treatment restored the PRA and the effects of captopril to a similar degree to the non-treated group. The acute hypotensive effects of captopril were reduced on the 10th week compared with the 7th week after renal arterial constriction in 2K, 1C RHR. The fall in blood pressure induced by captopril significantly correlated with the initial PRA both in the 7th and 10th week after clipping. There was a significant correlation between PRA and RRC of the clipped kidney. Rats previously treated with DOC-salt had either removal of the contralateral kidney with removal of the clip from the ischaemic kidney, or removal of the ischaemic kidney. Blood pressure fell to normal levels in the unclipped group and in the nephrectomy group, but the fall in the latter group was transient and within two weeks had risen to significantly higher levels than in the unclipped group. It is concluded that structural vascular change following DOC-salt hypertension is insufficient to cause persisting hypertension except when it occurs in the renal circulation.     

Mitral stenosis: evaluation with MR imaging after percutaneous balloon valvuloplasty

To evaluate the pathoanatomic findings of mitral valve stenosis and changes after percutaneous balloon valvuloplasty (PBV), magnetic resonance (MR) imaging was performed in 23 patients. The patients were imaged with a 2.0-T system within 1 week before and 3-10 days after PBV. The angle of the interatrial septum was measured on the transverse image to facilitate a successful transseptal puncture. On MR images, the mean transverse and anteroposterior diameters of the left atrium at the level of the aortic root in the ventricular diastolic phase decreased significantly after PBV. Areas of flow-related intraluminal signal intensity detected in the left atrial cavity of 17 patients (74%) before the procedure disappeared in 15 patients after the procedure. Other MR imaging findings after PBV were the disappearance of intraluminal signal intensity in the pulmonary artery, normal curvature of the interatrial and interventricular septa, and pericardial effusion as a complication. MR imaging was thought to provide useful information before and after PBV in patients with mitral stenosis.     

Coexistence of hyperplasia of renomedullary interstitial cells and juxtaglomerular cells after acute occlusion of renal artery

A left renal artery aneurysm was found in a 45-year-old normotensive man. In an attempt to evade the possible occurrence of aneurysmal rupture, aneurysmectomy in addition to left renal biopsy (first surgery) was performed. This vascular operation led to a virtually complete renal artery stenosis concomitant with the development of hypertension. The renin-angiotensin-aldosterone system and levels of plasma prostaglandins were also increased following this failed surgery. Reconstruction of the affected renal artery was technically so difficult that left nephrectomy was carried out (second surgery). Renal specimens obtained at the first surgery revealed no histological abnormalities. Discriminating histological findings of the kidney obtained at the second surgery were remarkable; hyperplasia of the juxtaglomerular cells producing renin and hyperplasia of the renomedullary interstitial cells which had pecularities similar to cells known to secrete renal prostaglandins. High levels of the renin-angiotensin-aldosterone system and plasma prostaglandins after the first surgery were reduced following the second surgery. It is suggested that acute constriction of the renal artery led to a hyperplastic change of the juxtaglomerular cells and the renomedullary interstitial cells and stimulated an inappropriate release of renin and renal prostaglandins.