Melricflash/CW_MedAbstractsAlt huggingface dataset:
The use of the Jarvik-7 total artificial heart and the Symbion ventricular assist device as a bridge to transplantation. The proliferation of transplantation programs has not been paralleled by a similar increase in the availability of organ donors. Between 1984 and 1987, 104 orthotopic heart transplantations were performed at Loyola University Medical Center. During the same period, 25 patients died while awaiting a donor organ. To reduce the mortality, we began using the total artificial heart (TAH) and a ventricular assist device (VAD) as a bridge to transplantation in 1988. Of 29 patients who underwent transplantation, 15 patients required a TAH and three patients required a VAD as a bridge. The underlying heart conditions were ischemic cardiomyopathy (11 patients), dilated cardiomyopathy (5 patients), giant cell myocarditis (1 patient), and allograft failure (1 patient). The average duration of mechanical support was 10 days (range, 1 to 35 days). Of the 17 patients who successfully underwent transplantation, 1 patient died at 17 days because of acute rejection of the transplanted heart, and another patient died at 14 days because of a cerebral vascular event. Fifteen patients (83%) were long-term survivors. Nine patients required reoperation for bleeding. While the mechanical device was in place, the activated clotting time was maintained between 170 and 200 seconds with heparin. Dipyridamole was given. We conclude that the TAH and VAD are excellent mechanical bridges to transplantation. 

Category: general pathological conditions
Left atrial to femoral arterial bypass using the biomedicus pump for operations of the thoracic aorta. Left atrial to left femoral arterial bypass is an approach to operations of the thoracic aorta dating back to the late 1950s. Since that time, various modifications of the basic bypass circuit have evolved. In addition, temporary bypass shunts have also been described in a variety of positions. The goals of bypass of the thoracic aorta regardless of the technique include prevention of distal hypoperfusion, which can lead to paraplegia, limb loss, multiple organ failure, and sometimes death. Recently, there have been reports of the use of the biomedicus centrifugal pump in bypass circuits of the thoracic aorta. Our series, as well as the success of others, using this variation of a traditional bypass circuit of the thoracic aorta, establishes the biopump's capability of minimizing inherent complications in the bypass circuit. 

Category: cardiovascular diseases
US-assisted aspiration thrombectomy: in vitro investigations. The authors describe the use of a new ultrasound (US)-aspiration thrombectomy technique. An oscillating US probe was inserted into a thin-walled, large-bore aspiration catheter. Experiments tested the ability of the new device and other catheter combinations to remove clot material from a Petri dish, as well as from small and large vessel models made of silicone and glass tubes, respectively. Results of the experiments demonstrated that an oscillating 1.0-mm US probe inserted into an aspiration catheter (7-9 F in diameter) promoted clot fragmentation and allowed continuous aspiration of thrombi of any size. When compared with simple large-bore catheter aspiration and with mechanical fragmentation by means of a US probe within a catheter that was flushed to cool the probe, US-assisted aspiration thrombectomy demonstrated significantly better results for percutaneous transcatheter removal of fresh thrombi. 

Category: cardiovascular diseases
Cardiac echinococcosis with fatal intracerebral embolism. A previously well 7 year old boy presented with sudden loss of consciousness and fitting. No evidence of trauma or space occupying lesion was identified. Death occurred the next day due to cerebral infarction caused by embolised fragments from a ruptured left ventricular hydatid cyst that was found at necropsy. 

Category: cardiovascular diseases
Poisoning with equine phenylbutazone in a racetrack worker. Phenylbutazone is a potent nonsteroidal, anti-inflammatory drug often used by veterinarians to treat racetrack animals. Its use in human beings is limited because of significant adverse effects and the availability of newer, safer drugs. We report the case of a 24-year-old man who ingested 17 g of equine phenylbutazone over a 24-hour period to treat the pain of a toothache. He developed grand mal seizures, coma, hypotension, respiratory and renal failure, and hepatic injury. Serum phenylbutazone concentration obtained approximately eight hours after presentation was 900 micrograms/mL. The patient recovered during six weeks of intensive supportive care and repeated hemodialysis. 

Category: nervous system diseases
Effect of hypoxia on cerebral metabolites measured by proton nuclear magnetic resonance spectroscopy in rats. Proton nuclear magnetic resonance spectroscopy is a unique method to monitor noninvasively the concentrations of cerebral metabolites. N-Acetyl-L-aspartate, the concentration of which is assumed to be stable during hypoxia, has been used to form ratios with lactate. To determine the stability of the signal from N-acetyl-L-aspartate, we used a model of graded hypoxia in rats to monitor the percentage changes from baseline of the peak heights for lactate, lipids, and N-acetyl-L-aspartate. Anesthetized adult rats were exposed sequentially to 15% and 10% O2 while proton nuclear magnetic resonance spectra were collected with a surface coil in a 7-T 89-mm-bore spectrometer. Brain lactate concentration was either increased by feeding or infusion of glucose (n = 9) or lowered by fasting (n = 7). After death the brains were removed and frozen, and the water- and lipid-soluble compounds were extracted to identify the origin of the signals. We analyzed the data both as the percentage change from baseline for heights of the lactate (1.33 ppm), lipids (1.5 ppm), and N-acetyl-L-aspartate (2.02 ppm) peaks and as the ratios of heights of the 1.33 and 2.02 and the 1.5 and 2.02 ppm peaks. Both hypoxic episodes caused a 45% decrease from baseline in the 2.02 ppm peak. During the second hypoxic episode, the 1.33:2.02 ppm peak height ratio increased significantly in hyperglycemic rats (p less than 0.05) but was unchanged in hypoglycemic rats. 

Category: general pathological conditions
Rupture of atheromatous plaque as a cause of thrombotic occlusion of stenotic internal carotid artery. We analyzed the clinical profiles and autopsy findings of five patients who died shortly after developing cerebral infarction following thrombotic occlusion of the internal carotid artery. In all five cases, thrombotic occlusion was caused by rupture of the fibrous lining over the gruel of atheroma at the origin of the internal carotid artery showing tight stenosis of the lumen. The mean +/- SD shorter diameter of the lumen at the site of occlusion was 1.5 +/- 0.4 mm. Our results show that an internal carotid artery with tight stenosis of the lumen by atheroma containing gruel harbors a risk of thrombotic occlusion, which may give rise to cerebral infarction by artery-to-artery embolism or by reduced cerebral perfusion. 

Category: cardiovascular diseases
Portacaval shunt versus endoscopic sclerotherapy in the elective treatment of variceal hemorrhage. Eighty-two consecutive Child-Campbell class A and B cirrhotic patients were included in a prospective controlled trial to assess the efficacy and safety of portacaval anastomosis vs. endoscopic sclerotherapy as elective treatment of variceal hemorrhage. Forty-one patients were randomized to portacaval anastomosis and 41 to sclerotherapy. After excluding dropouts, 34 patients were treated with portacaval anastomosis and 35 with sclerotherapy. The incidence of variceal rebleeding during follow-up (mean +/- SD, 20.6 +/- 14.2 months) was significantly higher in the sclerotherapy than in the portacaval groups, either considering the overall treated group or only patients completing sclerotherapy (40% and 25% vs. 2.9%; P = 0.0002 and P = 0.01, respectively). The 2-year probability of suffering from at least one episode of hepatic encephalopathy was significantly higher in patients submitted to portacaval anastomosis than in those treated with endoscopic sclerotherapy (40% vs. 12%; P = 0.04). However, disabling encephalopathy only appeared in 3 of 34 patients who underwent surgery (8.8%). Early and long-term mortality did not differ between the therapeutic groups; 2-year survival rates were 83% for portacaval anastomosis and 79% for sclerotherapy. It is concluded that portacaval anastomosis is more effective than endoscopic sclerotherapy in preventing variceal rebleeding in spite of the greater incidence of hepatic encephalopathy. The role of portacaval anastomosis in the elective treatment of variceal rebleeding should be reassessed. 

Category: nervous system diseases
Extracorporeal shock wave lithotripsy in combination with transurethral surgery for management of large bladder calculi and moderate outlet obstruction. In 5 men evaluated for symptoms of obstructive voiding flexible cystoscopy revealed large or multiple bladder calculi along with small to moderate prostatic enlargement. All patients had successful localization and fragmentation of calculi with the Dornier HM3 lithotriptor. Of these patients 4 underwent transurethral resection or incision of the prostate under the same epidural anesthesia for moderate prostatic obstruction without complication and 1 subsequently required suprapubic prostatectomy of a gland with a large middle lobe that made a transurethral operation difficult. Extracorporeal shock wave lithotripsy should be considered for the primary management of large or hard bladder calculi and it is of particular value in combination with a transurethral operation for patients with small to moderate prostatic obstruction. 

Category: general pathological conditions
Vitamin C and cancer prevention: the epidemiologic evidence. Epidemiologic evidence of a protective effect of vitamin C for non-hormone-dependent cancers is strong. Of the 46 such studies in which a dietary vitamin C index was calculated, 33 found statistically significant protection, with high intake conferring approximately a twofold protective effect compared with low intake. Of 29 additional studies that assessed fruit intake, 21 found significant protection. For cancers of the esophagus, larynx, oral cavity, and pancreas, evidence for a protective effect of vitamin C or some component in fruit is strong and consistent. For cancers of the stomach, rectum, breast, and cervix there is also strong evidence. Several recent lung cancer studies found significant protective effects of vitamin C or of foods that are better sources of vitamin C than of beta-carotene. It is likely that ascorbic acid, carotenoids, and other factors in fruits and vegetables act jointly. Increased consumption of fruits and vegetables in general should be encouraged. 

Category: neoplasms
Intraoperative transesophageal color-coded Doppler echocardiography for evaluation of residual regurgitation after mitral valve repair. Because mitral valve competence after mitral valve reconstruction is awkward to assess during this procedure, we evaluated in this respect transesophageal color-coded Doppler echocardiography in 23 patients undergoing mitral valve reconstruction for severe mitral regurgitation. Transesophageal echocardiographic examinations were performed after induction of anesthesia but before sternotomy (baseline), after mitral valve repair before decannulation, and at sternal closure, all at similar mean aortic pressure and echocardiographic instrument settings. The degree of mitral regurgitation by transesophageal color Doppler flow mapping was visually quantified on a 5-point scale (0 to 4), pending the left atrial extent of the regurgitant jet. This was compared with the degree of mitral regurgitation by left ventricular cineangiography performed within several weeks after operation and also visually quantified on a 5-point scale (0 to 4), with use of the right anterior oblique projection. There was good correlation between the two methods (r = 0.83; p less than 0.001). We conclude that residual mitral regurgitation, as assessed by transesophageal color flow mapping in the operating room, highly correlates with the ultimate mitral regurgitation by cineangiography. Therefore transesophageal echocardiography can be helpful for evaluation of mitral valve competence during mitral valve reconstruction, and hence, in case of repair failure, allow valve replacement in the same surgical session, thus avoiding reoperation. 

Category: cardiovascular diseases
A simple and sensitive microtiter plate estrogen bioassay based on stimulation of alkaline phosphatase in Ishikawa cells: estrogenic action of delta 5 adrenal steroids. We have developed an estrogen bioassay using the Ishikawa human endometrial adenocarcinoma cell line growing in 96-well microtiter plates. Alkaline phosphatase enzyme activity (AlkP) in these cells is markedly stimulated by estrogens, and this enzyme can be easily quantified in situ using a chromogenic substrate. These cells are very sensitive to estrogens; estradiol induces AlkP at levels as low as 10(-12) M. Antiestrogens completely block the action of estradiol. Various estrogens stimulate AlkP with potencies comparable to those achieved in vivo. The induction of AlkP is specific for estrogens; no other type of steroid, including androgens, progestins, mineralocorticoids, or glucocorticoids produce this effect. The stimulation of AlkP in Ishikawa cells is specific for estrogens, is highly reproducible and sensitive, and permits large numbers of samples to be assayed with ease. We have used this assay to investigate the estrogenic action of the adrenal delta 5-3 beta-hydroxysteroids. While pregnenolone is inactive, dehydroepiandrosterone and its sulfate ester induce AlkP slightly. However, the C19 steroid, 5-androstene-3 beta, 17 beta-diol is considerably more estrogenic in this assay, although it stimulates Ishikawa AlkP with a potency of 1/30,000 that of estradiol. The stimulation by 5-androstene-3 beta,17 beta-diol is inhibited by antiestrogens, but it is not blocked by the delta 5-3 beta-hydroxysteroid isomerase/dehydrogenase inhibitor, cyanoketone, or by the aromatase inhibitor, 4-hydroxy-androstenedione. Thus, neither conversion to a delta 4-3-ketone nor aromatization is required for the action of this unusual estrogen. 

Category: neoplasms
The diagnosis and management of aortic dissection. Aortic dissection is a severe disease. Most untreated patients with types I and II (proximal) dissection and over half of those with type III (distal) dissection die within 1 year. Most of the deaths occur within 2 weeks and are caused by rupture, aortic insufficiency, and branch vessel obstruction. Aortic dissection is suspected in patients with anterior chest and back pain that progresses downward. Diagnosis is confirmed by computed tomography, aortography, or echocardiography. Appropriate medical treatment and corrective surgery, including total aortic replacement, performed in the acute and chronic stages, are now successful in over 90% of the cases; long-term results of treatment are steadily improving and are expected to exceed 50% at 10 years. The keys to a successful outcome are being aware of the symptoms of dissection, early diagnosis, and prompt application of appropriate treatment; diligent follow-up includes controlling blood pressure, decreasing the velocity of left ventricular contraction, monitoring the size of the residual aorta, and taking appropriate action if redissection, aneurysmal formation, or rupture occurs. 

Category: cardiovascular diseases
Clinical nuclear magnetic resonance spectroscopy: insight into metabolism. Nuclear magnetic resonance (NMR) spectroscopy can nondestructively evaluate changes in metabolites with different disease states, as well as with therapeutic interventions. Animal studies have provided the basis for understanding changes in high-energy phosphates with myocardial ischemia. Studies of graded ischemia due to partial coronary stenosis have shown the sensitivity of the ratio of phosphocreatinine to inorganic phosphate to small reductions in myocardial blood flow and its relation to myocardial function. The application of NMR spectroscopy to humans requires precise localization techniques to avoid acquiring contaminating information from structures around the heart, such as the chest wall and diaphragm. With these localization techniques, metabolic evidence of ischemia has been demonstrated in patients with myocardial infarction and patients with known coronary disease, although the sensitivity of this technique for the diagnosis of inducible ischemia is unknown. At rest, patients with dilated and hypertrophic cardiomyopathies often have an elevated phosphodiester resonance, possibly signifying abnormal breakdown of membrane phospholipids. Increasing oxygen demand in these patients does not usually alter high-energy phosphates, suggesting that oxidative energy metabolism is preserved under these conditions. NMR spectroscopy is a powerful tool to increase understanding of metabolic changes in a variety of pathologic conditions. 

Category: cardiovascular diseases
Successful treatment of an excimer laser-associated coronary artery perforation with the Stack perfusion catheter. A 64-year-old woman underwent excimer laser angioplasty of the right coronary artery. The procedure was complicated by perforation, which was successfully managed without complication with a Stack perfusion catheter. This report describes successful nonsurgical treatment of laser-induced coronary perforation and makes recommendations for avoiding this complication in other patients. 

Category: general pathological conditions
Flow cytometric evaluation of chemosensitive and chemoresistant head and neck tumors. For patients with head and neck squamous carcinoma, a clinical response to induction chemotherapy has correlated with a survival advantage. Similarly, patients with diploid tumors have displayed a survival advantage when compared with patients with aneuploid tumors. This study examined DNA content in 33 patients who had undergone induction chemotherapy as part of two clinical protocols to determine if there was a correlation between the patients with diploid tumors and the patients with a clinical response to chemotherapy. Although patients with stage III tumors had a longer disease-free survival than stage IV patients (p less than 0.0002), the addition of DNA content information did not improve the ability to predict response. Specifically, there was no correlation between DNA content and the response to chemotherapy. In addition, for this group of patients, a diploid DNA content was not correlated with a survival advantage. We conclude that DNA content information did not add significantly to the prediction of clinical outcome in these patients who received induction chemotherapy. 

Category: neoplasms
Anterior segment ischemia: a complication of retinal detachment repair in a patient with sickle cell trait. Anterior segment ischemia (ASI) is a dreaded complication of retinal detachment surgery particularly in patients with predisposing factors such as sickle cell disease. We report a case of ASI after scleral buckling in an otherwise healthy black patient with sickle cell trait. Conditions of relative hypoxia intraoperatively from either anesthesia or surgical manipulation may precipitate vasoocclusive phenomena in these normally asymptomatic patients. Since the incidence of sickle cell trait in the black population in the United States is 8.5%, we recommend these patients have a preoperative sickle test followed by hemoglobin electrophoresis with quantification if positive. The presence of sickle cell trait should alert the surgeon to the risk of ASI, and factors predisposing to hypoxia should be minimized when possible. 

Category: cardiovascular diseases
Transesophageal echocardiography during percutaneous balloon mitral valvuloplasty. To ascertain the value of transesophageal echocardiography during percutaneous balloon mitral valvuloplasty, the present study was undertaken in 26 anesthesized patients (21 women and 5 men; mean age, 47 years) with symptomatic rheumatic mitral valve stenosis. In all but one patient the balloon dilation of the mitral valve was successful and Doppler-derived valve area increased (0.9 +/- 0.3 to 1.9 +/- 0.4 cm2). Transesophageal echocardiography provides continuous monitoring, as well as guidance of the procedure. Crossing the arterial septum, as well as delivery of the sheath through the mitral valve orifice and correct positioning of the balloon, was highly facilitated and reduced x-ray exposure time. The degree of mitral regurgitation and the presence of interatrial shunting at the end of the procedure could be readily assessed, making cineangiography not necessary. Complications of the procedure, such as pericardial effusion, could be detected before hemodynamic deterioration had occurred (one patient). The advantages of transesophageal echocardiography for routine monitoring of percutaneous mitral valvuloplasty, however, should be weighted against the added risk and expense of this support. 

Category: cardiovascular diseases
Chronic posterior subluxation and dislocation of the radial head. The clinical and radiographic features of chronic posterior subluxation or dislocation of the radial head were studied in thirty-four elbows of twenty-seven patients. Three characteristic radiographic types were noted: Type I, subluxation; Type II, posterior dislocation with minimum displacement; and Type III, posterior dislocation with substantial proximal migration of the radius. Follow-up of eighteen patients (twenty-one elbows) revealed that posterior displacement did not usually cause serious functional impairment except for loss of rotation of the forearm. The least common presentation, Type-I subluxation, caused pain and clicking and was associated with late degenerative arthritis. Cosmetic deformity due to prominence of the radial head was also a cosmetic problem, particularly with Type-III dislocation. 

Category: general pathological conditions
An improved photochemical model of embolic cerebral infarction in rats. To provide further evidence that the multiple cerebral infarcts found in rats following photochemical damage to the carotid artery are caused by emboli and to eliminate the systemic hypotension and heating of the blood reported with the previous photochemical embolic stroke model (rose bengal and a green laser), I have modified the photochemical technique. Brain pathology was studied in 18 Wistar rats following carotid artery irradiation with a red laser (632 nm) at powers ranging from 100 to 800 mW/cm2 for 10 or 20 minutes following the injection of the photosensitizing dye Photofrin II. Multiple cerebral arterioles were occluded by platelet aggregates containing frequent erythrocytes and leukocytes, identical to the thrombotic material in the carotid artery but different from the platelet aggregates seen in the carotid artery and the brain in the rose bengal model. Eighty infarcts were distributed randomly throughout the brain ipsilateral to the nonocclusive carotid thrombus. Significant heating (0.5 degree C or more) of the blood occurred only with laser powers higher (1,600 mW/cm2) or laser irradiations longer (25 minutes) than those used in the improved model of embolic stroke. This model mimics one mechanism of stroke in humans and provides a means to study systematically the morphological evolution of small cerebral infarcts. 

Category: cardiovascular diseases