Symptomatic subclavian steal syndrome four decades after operation for dysphagia lusoria

Congenital abnormalities of the aortic arch may lead to signs and symptoms of tracheal and esophageal obstruction secondary to a restrictive vascular ring. There are many case reports and monographs concerning the surgical management of dysphagia lusoria. This case provides the first example of long-term follow-up of surgical intervention for relief of dysphagia lusoria. A 45-year-old laborer presented with a several year history of episodic bilateral blindness and a more recent onset of "drop attacks." Notably this patient had presented at the age of 18 months with difficulty breathing and eating since birth. The patient also had frequent upper respiratory infections and episodes of pneumonia. Workup revealed a right-sided aortic arch with a left ligamentum arteriosum. When he was first seen in our clinic, history and physical examination revealed claudication and diminished pulses in the left upper extremity. Arteriography and duplex studies confirmed reversal of flow in the patient's left vertebral artery. The arteriogram demonstrated the presence of a right-sided aortic arch and descending aorta along with the proximal stump of the previously ligated left subclavian artery. He underwent left carotid to left axillary artery bypass for the treatment of symptomatic subclavian steal syndrome. His symptoms have resolved with return of antegrade vertebral flow and the presence of normal pulses in the left arm. Congenital aortic abnormalities that lead to tracheal and esophageal compromise are numerous and varied. Surgical management requires a thorough understanding of the person's anatomy and preoperative planning. The life expectancy of patients with dysphagia lusoria necessitates consideration of the long-term consequences of surgical intervention.     

Evaluating medication response in ADHD: cognitive, behavioral, and single-subject methodology

We introduce a novel application for linkage analysis: using bone marrow donor-recipient sib pairs to search for genes influential in graft-versus-host disease (GVHD), a major cause of morbidity and mortality following allogeneic bone marrow transplantation. In particular, we show that transplant sib pairs in which the recipient developed severe GVHD can be used to map genes in the same way as traditional discordant (affected/unaffected) sib pairs (DSPs). For a plausible GVHD model, we demonstrate that the transplant/discordant sib pair analog of the "possible triangle test" [Holmans (1993) Am J Hum Genet 52:362-374] has similar power to that of the simpler "restricted test" proposed by Risch [(1990b) Am J Hum Genet 46:229-241; (1992) Am J Hum Genet 51:673-675]. Moreover, we show that the restricted test has superior power in much of the DSP possible triangle and significantly inferior power in only a small region. Thus, we conclude that the restricted test is preferable for localizing genes with transplant/discordant sib pairs. Finally, we examine the effects of heterogeneity on the power to detect GVHD loci and demonstrate the gain in efficiency by dividing the sample into genetically more homogeneous subgroups.     

Diagnosis and treatment of aortic valve stenosis

The present review has attempted to summarize the classic symptoms and signs of aortic valve stenosis, especially in an adult. It is emphasized that all the classic signs rarely are present and their absence may mislead an unwary clinician. The diagnostic help provided by noninvasive tests, including echocardiography and phonocardiography, has been emphasized. A need for cardiac catheterization and angiography in most patients prior to corrective surgery is stressed. The natural history of the disease without operative intervention is dim and a significant risk of sudden death exists. The current surgical approach with immediate and long-term results is summarized. Finally, attention has been drawn to the special clinical circumstances when the aortic valve stenosis provides a strinkingly different clinical picture. We cannot find a better way to end this review than by quoting a warning note given by Thomas Lewis in 1920: "It is the faint cry of an anguished and fast failing muscle, which, when it comes, all should strain to hear, for it is not long repeated. A few months, a few years at most, and the end comes."     

Perforating pseudoxanthoma elasticum. Its distinction from elastosis perforans serpiginosa

It is not generally appreciated that pseudoxanthoma elasticum (PXE) can be associated with epidermal perforation by elastic fibers. We report an example of this phenomenon. The term "perforating PXE" is suggested and a distinction is made from elastosis perforans serpiginosa (EPS). We believe that most reported cases of coexistence of PXE and EPS are perforating PXE and that the coexistence of EPS has not been clearly demonstrated.     

Differential effects of nerve impulses on adrenergic storage vesicles in rat heart

The effects of increasing and decreasing activity in sympathetic neurons on light (D420 = 1.05) and heavy (D420 = 1.15) populations of adrenergic vesicles have been determined. Norepinephrine (NE) was used as a marker for the soluble contents of the vesicles, and dopamine beta-hydroxylase was used as a marker for the vesicle membranes. Cold exposure was used to increase activity in the sympathetic nervous system. A 40% decrease in the NE content of the rat heart with no change in the activity of dopamine beta-hydroxylase was observed after 70 minutes at 5 degrees C. The fall in NE content was completely blocked by pretreating the animals with chlorisondamine. Separation of light and heavy populations of vesicles was achieved with linear sucrose density gradients. Cold stress of 70 minutes duration led to a marked decrease in the NE content of the light vesicles. Blocking adrenergic nerve impulses with chlorisondamine resulted in an increase in total NE in the heart but had no effect on dopamine beta-hydroxylase activity. The initial effect of chlorisondamine was to increase the NE content of the light vesicles. The administration of alpha-methyl-p-tyrosine for 6 hours caused an approximately equal loss of NE from both vesicle populations. The decrease in total heart NE was about 25% and could be prevented by pretreating the animals with chlorisondamine. These results suggest that the light vesicle fraction is involved in the rapid or short-term responses to changes in nerve impulse frequency. Changes in the NE content of the heavy vesicles in rat heart were seen only after longer times, suggesting that these particles may function only as auxiliary storage sites for the neurotransmitter.     

The effect of intermittent carbon monoxide exposure on experimental atherosclerosis in the rabbit

(1) Twenty-four female New Zealand White rabbits were fed commercial diet plus 2% cholesterol. Twelve of these animals were exposed to carbon monoxide for 4 hours per day, seven days per week for 10 weeks. The carbon monoxide exposure was such that the mean blood carboxy-haemoglobin was raised to approximately 20% during each exposure period. Twelve control animals breathed atmospheric air under the same conditions of confinement as the carbon monoxide-exposed group. (2) No significant differences in the plasma levels of cholesterol, triglycerides or glutamate oxalacetate transaminase were observed between the two groups during the experiment. (3) When the animals were sacrificed at the end of the experiment no significant differences were observed between the two groups in the aortic content of triglycerides, cholesterol or phospholipids. (4) The extent of coronary artery atherosclerosis was statistically significantly higher in the carbon monoxide group than in the control group. (5) Ultracentrifugal analysis of plasma lipoproteins revealed that there was significantly more cholesterol in the d less than l.006 fraction from the CO-exposed rabbits. (6) These findings, are discussed with particular reference to the claim that the causal agent in tobacco smoke associated arterial disease is carbon monoxide.     

Effect of high amounts of dietary zinc and age upon tissue zinc in young chicks

Weight gains of younger broiler chicks were not reduced by up to 2400 p.p.m. added zinc fed to four weeks of age. Tissue zinc was not changed significantly by 600 or 1200 p.p.m. supplemental dietary zinc, but at 2400 p.p.m. added zinc, blood, kidney, and liver zinc were significantly elevated (P less than 0.05). In the heart, zinc was not affected by the added dietary zinc but increased over time with all diets. Unlike the calf and weanling pig, the metabolism of zinc in the young chick does not appear to change appreciably with increasing maturity. Thus, the homeostatic control mechanisms of the young chick are effective for up to 1200 p.p.m. dietary zinc, but are partially overcome by 2400 p.p.m. added dietary zinc.