Pumping and clearance function of the eustachian tube

The purpose of this study was to clarify the relationship between mucociliary and muscular clearance in the eustachian tube. Displacement of various viscosities and volumes of a colored fluid through the tube was observed endoscopically in cats. To test ciliary clearance, the fluid was placed in either the tympanum or the mastoid bulla. The interval between the instillation and beginning of discharge of the fluid from the pharyngeal orifice of tube was measured. Clearance time was prolonged with fluids having high viscosities, and the clearance time from the tympanum was shorter than that from the mastoid bulla. To test muscular clearance, the tensor veli palatini muscle was stimulated electrically to simulate swallowing, and the number of contractions necessary for massive discharge of the fluid was counted. Massive discharge occurred only with low viscosity fluid placed in the tympanum, whereas small amounts of highly viscous fluid were cleared by linear discharge. The authors concluded that when the volume of middle ear effusion was small, the fluid was cleared by mucociliary clearance. When the volume of fluid was large, the low viscosity fluid was cleared by muscular clearance only, while highly viscous fluid was cleared both by ciliary and muscular clearance.     

Effects of coronary arteriography on atrioventricular conduction. Studies with His bundle electrography.

The effect of coronary arteriography on atrioventricular (A-V) conduction was studied in 26 patients with the use of His bundle electrography. Slowing of atrioventricular conduction (prolonged A-H interval) was observed in all 26 pateints following either left or right coronary arteriography without a detectable change in the H-V interval. In four patients with left coronary preponderance in arterial distribution pattern, prolonged A-H inverval was produced only by injecting the contrast material into the left coronary artery. Conversely, in the remaining 22 patiens either with right preponderance or balanced distribution, prolongation of the A-H time was a result of opacification of the right coronary artery. The A-H interval at peak prolongation (133.9 +/- 18.7 [S.D.] msec.) was significantly higher than the control measurement (98.3 +/- 15.7 msec.) (P less than 0.0001). Prolongation of the A-H interval started around 4 seconds after the initiation of injection, reached its peak at an average of 7.7 seconds, and subsided within 20 seconds. When intracoronary injection of 6 ml. of normal saline was made in these 26 patients, no change was observed in the His bundle electrograms. On the other hand, hypertonic (20 per cent) glucose solution, when injected into coronary arteries, had an effect remearably similar to that of contrast material on A-V conduction. These findings suggest that prolonged A-H interval observed during coronary arteriography may be a result of osmotic effect of the contrast material, rather than hypoxia resulting from dilution of coronary blood flow.     

Surgical treatment strategy for hepatocellular carcinoma in patients with impaired liver function: hepatic resection or radiofrequency ablation?

Background

To compare the survival impacts of radiofrequency ablation (RFA) as an initial treatment for hepatocellular carcinoma (HCC) in patients with impaired liver functional reserve compared to those of hepatic resection (HR).

Mucoepidermoid carcinoma of the hard palate

A case of mucoepidermoid carcinoma originating in the hard palate was presented. Histological diagnosis of the removed mass at the first operation was pleomorphic adenoma. Tumor recurred at the same site three years later. Subtotal maxillectomy was performed and recurrent tumor was histologically diagnosed as low grade malignant mucoepidermoid carcinoma. A two-year follow-up showed no evidence of recurrence. The low grade malignant mucoepidermoid carcinoma strongly resembles pleomorphic adenoma. The differential diagnosis is important for the better treatment and prognosis.     

Pain Response Rates After Conventional Radiation Therapy for Bone Metastases in Prospective Nonrandomized Studies: A Systematic Review

Purpose

This study aimed to determine the pain response rates after conventional radiation therapy (RT) for painful bone metastases in prospective nonrandomized studies, which better reflect daily practice than randomized controlled trials.

Implication of primary tumor location for the indication of preoperative chemotherapy in patients with colorectal liver metastases

Background

The benefit of preoperative chemotherapy for colorectal liver metastases (CRLM) remains uncertain. The aim was to clarify the effect of preoperative chemotherapy on CRLM according to the primary tumor location.

Sinus slowing produced by intracoronary arterial injections of hyperosmotic solutions in man.

The effect of intracoronary arterial injections of normal saline, contrast agent, hyperosmotic glucose, and mannitol solutions on the sinus rate was studied in 18 patients. Sinus slowing was not produced by isosmotic saline (0.3 Osm. per kilogram of water) when injected into either coronary artery, whereas 76% Urografin (1.9 Osm. per kilogram of water), 20% glucose (1.3 Osm. per kilogram of water), and mannitol (1.2 Osm. per kilogram of water) decreased the sinus rate significantly (P less than 0.001). Among these solutions, Urografin with the highest osmolality produced the most marked sinus slowing, whereas no significant difference was detected between change in the sinus rate with hyperosmotic glucose and mannitol solutions (P greater than 0.5). Moreover, there was no significant difference between the degree of sinus slowing produced by intracoronary injections into the coronary artery of the side which the sinus node artery originated from and the slowing produced by contralateral injections with hyperosmotic solutions (P greater than 0.2). Therefore, it seems unlikely that this sinus slowing would be a result of a direct action on the sinus node including hypoxia and elevated perfusion pressure. Reflex-mediated parasympathetic stimulation may be operative.