Is cost containment working?
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to K Davis.
Explore the source record for details and available documents.
The clinical course and outcome of hydrocephalus diagnosed in utero is not well understood. To approach this problem 40 cases were reviewed of intrauterine fetal hydrocephalus diagnosed with sonography, and follow-up information was obtained regarding them. Sonograms were evaluated for cerebral dimensions, biparietal diameter, brain mantle size, ventricular ratio, amount of amniotic fluid, and associated abnormalities. Neonatal brain sonograms and computed tomographic (CT) scans were reviewed also. Clinical charts were reviewed for maternal age and parity, referral source, family history, fetal age at diagnosis and delivery, mode of delivery, physical examination and/or autopsy findings, karyotype, amniotic alpha 1 fetoprotein level, cause of death, shunt placement after birth, and status of live infants. The observations indicate that the prognosis for fetal hydrocephalus is poor. Only six infants (15%) were alive after an average follow-up of 13 months. Three children were normal and the other three had neurologic abnormalities ranging from severe (paralysis and incontinence) to minimal (2-3 months delayed motor development). Thirty-four fetuses or neonates died. Nine families elected to terminate pregnancy. Ten opted for decompression at delivery for progressive hydrocephalus. Neural tube defects were present in 12 of 23 infants at delivery. Fourteen other infants had additional significant congenital abnormalities. Other abnormal sonographic findings included polyhydramnios (13 of 38), oligohydramnios or decreased fluid (nine of 38), neural tube defect (nine of 40), and other congenital abnormalities (nine of 40). These findings indicate that hydrocephalus diagnosed in utero by sonography is caused by a heterogeneous group of disorders. In general, the prognosis for normal development is poor. Individual prognoses, however, depend on the specific malformations and the interventions used.
The rationale for, methodology of, and experience with intra-arterial BCNU infusion therapy of malignant glioma are described. This approach achieves tumor levels of drug four times greater than equal doses infused intravenously, and has been used to treat 79 patients over the course of 4 years. The drug was given in 192 infraophthalmic and 66 supraophthalmic carotid artery infusions. Patients who were treated via infraophthalmic carotid artery infusion following tumor recurrence (after both operation and irradiation) survived 54 additional weeks (92 weeks after initial diagnosis). Patients who were treated with BCNU immediately after initial irradiation therapy survived 64 weeks (infraophthalmic carotid artery infusion) and 49.5 weeks (supraophthalmic carotid artery infusion). The major ocular complications (pain and diminished visual acuity) associated with infraophthalmic carotid artery infusion are avoided by selective balloon-guided supraophthalmic carotid artery administration. However, both approaches were associated with white-matter changes, seen as diminished absorption on computerized tomography scans, in 20% of patients treated following irradiation therapy. This toxicity appears to preclude intra-arterial BCNU treatment in the immediate postirradiation period. Better results are being achieved with our current therapy, which involves four infusions of BCNU (400 mg every 4 weeks) into the infraophthalmic or supraophthalmic carotid artery in advance of irradiation. Cisplatin infusions (60 to 90 mg/sq m every 5 weeks) are offered for recurrent glioblastoma.
Survival data after 8 years of follow-up for all patients and after 7 years for certain subgroups are reported from CASS, a randomized trial of surgical or medical treatment assignment in patients with coronary artery disease who have less than severe angina or are asymptomatic after myocardial infarction. After 8 years, survival curves are not significantly different between medical and surgical groups; 87% of patients assigned to surgical and 84% of those assigned to medical treatment are alive. A significant advantage favoring surgical assignment was observed in patients with three-vessel disease and reduced ejection fractions (less than 0.5. but greater than 0.35); after 7 years of follow-up, 88% of the patients in the surgical group and 65% of those in the medical group are alive (p = .009). Survival curves for patients with normal resting ejection fractions are identical after 7 years. We conclude that the CASS trial reveals a significant advantage favoring surgical therapy in patients with three-vessel disease and impaired ventricular function who are randomly assigned to treatment.
"Cutting" of actin filaments by villin was evaluated from the time course of filament depolymerization. Depolymerization was initiated by diluting polymerized actin, labeled with a fluorescent probe on either lysine-374 or cysteine-375, to a concentration well below the critical into a medium containing free villin and various concentrations of calcium (in addition to potassium and magnesium). It was observed that at high calcium concentrations (200 microM) the time course of depolymerization could not be described by the single exponential that defines it at low calcium and low villin levels. Instead, at high calcium, the exponent increased with time and the rate of depolymerization became greater than that of controls in the absence of villin. This contrasts with the inhibition of depolymerization by villin at low calcium. The latter inhibition is a consequence of the capping of the barbed filament end by villin as are the inhibition of filament elongation and the elevation of the critical concentration. Evidence is presented that the effects of villin at high calcium are the result of cutting of the actin filaments by villin. It thus appears that different calcium binding sites control capping and cutting and that the calcium binding sites regulating cutting have a much lower affinity for calcium than the sites regulating capping of the barbed filament ends.
The heat-sensitive mutation of Drosophila melanogaster l(3)c4(3)hs1, causes mutant larvae raised at a restrictive temperature to have abnormally large wing discs. The large size of these discs is a disc-autonomous property and results from an increase in the number rather than the size of wing disc cells. We have used wing discs from this mutant to further investigate properties of transdetermination which had previously been investigated with nonmutant discs. Transdetermination can occur in nonmutant discs when the proliferative phase of imaginal disc development is extended by wounding discs and culturing them in vivo. The results indicate that additional proliferation in the absence of wounding does not lead to transdetermination. There is a correlation between the extent of growth of a cultured disc and the probability that it will undergo transdetermination. The results suggest that this correlation does not depend on a differential rate of cell division. Finally, the results indicate that the cells which give rise to transdetermination are at an equivalent developmental stage no later than that characteristic of eye-antenna disc cells before the third larval instar.
A case report of life-threatening hemorrhage from a congenital renal arteriovenous malformation during pregnancy is presented. The hyperdynamic circulatory state that exists during pregnancy may predispose to bleeding from vascular malformations. We review the classification and clinical presentation of renal arteriovenous malformations.
This paper reviews the major features of the new DRG prospective payment system which was introduced for the payment of hospitals under the Medicare program October 1, 1983 in the United States. It explores its general implications for the health sector, and then examines its specific implications for the development, diffusion, and utilization of medical technology. It concludes with some of the research questions that require investigation to provide an informed basis for modification to the payment system that will ensure that quality health care will be provided at an affordable cost.
We studied quantitative aspects of coronary artery contraction in isolated epicardial coronary ring segments from 49 human hearts. The order of maximal tension developed by drugs in normal calcium (ionized calcium, 1.26 mM) solution was U-44069 (a prostaglandin endoperoxide analog) greater than histamine greater than carbachol greater than serotonin greater than phenylephrine greater than ergonovine. In Ca2+-free solution these same drugs mediated a lesser degree of contraction, which demonstrates that the human coronary artery uses both "intracellular" and "extracellular" calcium in hormone receptor-activated contraction. U-44069, histamine, carbachol, and phenylephrine produced calcium-free/normal calcium maximal responses of 62.9% 48.7%, 39.8%, and 37.2%, respectively. Morphologic characteristics of the atherosclerotic plaques within the vessel lumen and the degree of myocardial dysfunction did not qualitatively alter these contractile responses. However, severely atherosclerotic coronary segments were supersensitive to histamine, but not to carbachol or calcium. In conclusion, the human epicardial coronary artery is a highly reactive vessel that uses at least two calcium pools to couple contraction. Receptor-coupled agonists differ in their abilities to mediate contraction and in the degree to which each calcium pool is used, and the presence of atherosclerosis potentiates the contractile response to histamine.
We studied isolated ring segments from a number of sites along the course of epicardial coronary arteries from 24 human hearts in order to characterize regional responsiveness to vasoactive agents. Concentration-response curves revealed heightened sensitivity to histamine in the proximal portion of the coronary arteries, and increased sensitivity to carbachol in the distal portion of these same vessels. In contrast, the response to stimulation by calcium or phenylephrine was uniform throughout the length of the vessels examined. These data suggest that regional variations in agonist response reflect heterogeneity in receptor populations along the course of the human epicardial coronary artery.
The original and continuing promise of Medicare can be preserved only through a complex package of fiscal reforms. Central to this should be a merger of Hospital Insurance and Supplementary Medical Insurance into a single Medicare trust fund, financed in part through income-related beneficiary premiums. Benefits could be expanded, while improving access and equity.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Combined proximal left anterior descending and proximal left circumflex artery stenoses greater than or equal to 70% have been referred to as "left main equivalent" lesions. We compared the survival rates of medically treated patients who have this type of coronary anatomic characteristics with the survival rates of patients who have left main coronary artery stenoses greater than or equal to 70% by use of a stratified life table approach and a Cox regression model. Comparison of the patients with left main coronary artery stenoses with those who have left main equivalent lesions by use of life table analysis and three different calculations of patient exposure time revealed a poorer prognosis for the patients who had left main coronary artery disease (p less than or equal to .04 for all three methods). The stepwise Cox analysis also determined that patients who had left main artery stenoses had a significantly poorer prognosis than patients who had left main equivalent coronary disease (p = .002), even after consideration of important baseline variables known to affect survival rates. We then compared the patients who had combined proximal left anterior descending and proximal left circumflex artery disease with patients who had combined stenoses greater than or equal to 70% in the nonproximal left anterior descending stenosis influenced survival rates. The 5 year to determine if location of the left anterior descending stenosis influenced survival rates. The 5 year survival rate was not as high for the patients who had proximal left anterior descending artery disease (55% vs 70%, p = .001). In conclusion, combined proximal left anterior descending and proximal left circumflex artery disease identifies a high-risk (as determined by angiography) patient subset.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We tested the effects of the calcium antagonists lanthanum, diltiazem, and flunarizine on the development of atherosclerosis in rabbits fed a 2% cholesterol diet. The drugs were given orally and were well tolerated. In the cholesterol control animals, 52.2% of the thoracic aortic intimal surface was Sudan IV positive. This was reduced by 37% (p less than 0.05) with lanthanum, 37% (p less than 0.05) with diltiazem, and 34% (p less than or equal to 0.06) with flunarizine. In all cholesterol-fed animals, the intramural, but not subepicardial, coronary arteries were severely diseased. The extent and distribution of this disease were not altered by the various drug interventions. Thus, the calcium antagonists lanthanum, diltiazem, and flunarizine suppress atherogenesis of the rabbit aorta but have no effect on the extent or distribution of atherosclerosis in the intramural coronary arteries.