Between January 1977 and January 1990, 44 patients with symptomatic vascular rings/slings required surgical intervention at this center. Nineteen patients had double aortic arch (group I); 13 patients had vascular ring consisting of right aortic arch, anomalous origin of the left subclavian artery, and ligamentum arteriosus (group II); eight patients had innominate artery compression (group III); and four patients had pulmonary artery sling (group IV). Three patients had complex congenital heart defect and died secondary to it and are excluded from the study. Follow-up was obtained on 31 patients (76%). The follow-up period ranged from 0.4 years to 10.9 years, with a mean of 3.6 years. Seventy percent of the overall group were asymptomatic, and 30% of patients continued to have upper and lower respiratory symptoms on late follow-up. One third of patients in groups I and II, who underwent surgical repair, continue to have symptoms. Patients who have persistent symptoms should be further evaluated with PFTs, MRI, and bronchoscopy, and may benefit from aortopexy. Patients with innominate artery compression and pulmonary artery sling do well soon after surgery with relief of most of their symptoms.

Airway Obstruction↗

PubMedDate not supplied

The acetylcholine receptors of the semicircular canal in the frog (Rana pipiens).

We present preliminary evidence that acetylcholine has three distinct modes of action on the discharge rate of afferent fibers from the frog isolated semicircular canal. These are: (I) a facilitatory effect which is of mixed muscarinic-nicotinic type and is mediated by a receptor which we call "atropine-preferring'; (II) a suppressive effect unmasked by atropine and antagonized by strychnine whose action is mediated by a "strychnine-preferring" receptor; (III) a suppressive effect produced by the cholinesterase inhibitors eserine and echothiophate, which being antagonized by curare, is mediated by a "curare-preferring" receptor.

Acetylcholine↗

PubMedDate not supplied

Advances in imaging of lymph flow disorders.

Conventional oil-contrast lymphography has long been the mainstay for lymphatic imaging. However, the emergence of computed tomography (CT) and magnetic resonance (MR) imaging has severely curtailed its use. Because of recent improvements and refinements, lymphangioscintigraphy now permits high-resolution imaging of peripheral lymphatic vessels and provides insight into lymph flow dynamics. It is indispensable for patients with known or suspected lymphatic circulatory disorders in confirming the diagnosis and delineating the pathogenesis and evolution of lymphedema. In addition, lymphangioscintigraphy helps evaluate lymphatic truncal anatomy and radiotracer transport. It can also be used to evaluate the efficacy of various treatment options designed to facilitate lymph flow or reduce lymph formation. The procedure is essentially noninvasive, can easily be repeated, and does not adversely affect the lymphatic vascular endothelium. MR imaging complements lymphangioscintigraphy in the monitoring and treatment of more complex lymphatic circulatory disorders, whereas CT facilitates catheter-guided percutaneous sclerosis or obliteration of specific lymphangiectasia or lymphangioma syndromes. Ultrasonography has proved useful in the setting of filariasis. Patients with a provisional diagnosis of peripheral lymphatic dysfunction or idiopathic edema should undergo diagnostic lymphangioscintigraphy and, in some cases, MR imaging to verify diagnostic accuracy, pinpoint the specific abnormality, and help guide subsequent therapy.

Diagnostic Imaging↗

PubMedDate not supplied

Cholinomimetics mimic efferent effects on semicircular canal afferent activity in the frog.

Acetylcholine (Ach) has received strong support as the neurotransmitter at vestibular efferent nerve endings. Ach, cholinomimetics and cholinergic antagonists were therefore applied to frog isolated whole labyrinths and isolated semicircular canals. Both spontaneous and evoked single unit and multiple unit activities were recorded from the decentralized posterior semicircular canal afferent nerve. In a manner analogous to efferent nerve stimulation, Ach produced both facilitatory and inhibitory changes in afferent firing rates. The facilitatory effect is likely mediated by muscarinic receptors (i.e. atropine antagonizes it at low concentrations). The facilitatory effect can also be elicited by muscarine and carbachol and it is likely produced presynaptically on the vestibular sensory cell. That is, the effects of Ach are not changed by removal of the efferent neurons but they are absent when afferent transmitter release is blocked. The inhibitory effect is not as well characterized as is the facilitatory effect but it can be blocked by strychnine. The results are consistent with the hypothesis that Ach is the transmitter responsible for both the facilitatory and the inhibitory effects of efferent vestibular nerve stimulation.

Acetylcholine↗

PubMedDate not supplied

Simultaneous radiotherapy for prostate cancer: 125I prostate implant followed by external-beam radiation.

PURPOSE: Using a rigorous prostate-specific antigen definition of disease-freedom, the 10-year disease-free survival rates after simultaneous radiation of prostate cancer are presented. PATIENTS AND MATERIALS: From January 1984 through December 1996, 1020 men with clinical stage T1T2N0 prostate cancer were treated by simultaneous radiation: radioactive 125I prostate implantation followed by external-beam radiation. The median pretreatment prostate-specific antigen was 7.5 ng/mL (range, 0.2-188 ng/mL). Implantation was performed by both the retropubic and the transperineal technique, always followed by external-beam radiation. None received hormone treatment. Disease freedom is defined as achieving and maintaining a posttreatment prostate-specific antigen of < or = 0.5 ng/mL. The median follow-up is 3 years (range, 1-14 years). RESULTS: The overall 5- and 10-year disease-free survival rates are 79% and 72%, respectively, after which a plateau is reached. At 5 years posttreatment, significantly better disease-free survival results are documented with simultaneous radiation by the ultrasound technique (92%) compared with the retropubic implant technique (73%). On multivariate analysis, pretreatment prostate-specific antigen is the most significant factor associated with disease-free survival, followed by implant technique. DISCUSSION: The 10-year disease-free survival rate after simultaneous radiation is comparable to the 10-year results after radical prostatectomy. Disease freedom is defined by the same prostate-specific antigen criteria used for surgery. A plateau in the disease-free curve suggests cure. Of equal importance, the information described in this report should form only a baseline relative to future results as men treated with simultaneous radiation using the transperineal implant technique reach longer follow-up.

Aged↗