123rc/medical_text huggingface dataset:
Hepatic injury induced by bile salts: correlation between biochemical and morphological events. Continuous intravenous infusion of taurochenodeoxycholate at a rate of 0.4 mumol.min-1.100 gm-1 for only 30 min in rats caused threefold to tenfold greater release of proteins (alkaline phosphatase, lactate dehydrogenase and albumin) into bile in comparison with animals infused with tauroursodeoxycholate at much higher rates (1.8 mumol.min-1.100 gm-1) for 2 hr. The simultaneous infusion of tauroursodeoxycholate and taurochenodeoxycholate (0.6 and 0.4 mumol.min-1.100 gm-1, respectively) for 2 hr prevented the marked biochemical changes in the bile induced by taurochenodeoxycholate for 15 to 60 min exhibited significantly more necrotic hepatocytes, especially in zone 1, in comparison with animals infused with tauroursodeoxycholate or a combination of taurochenodeoxycholate and tauroursodeoxycholate. A good correlation was observed between biochemical and morphological indices of bile acid-induced hepatocyte injury. These data suggest that (a) primary events induced by the acute infusion of toxic bile salts responsible for cholestasis include zone 1 hepatocellular necrosis and (b) this can be prevented by the simultaneous infusion of tauroursodeoxycholate.
Transient myocardial ischaemia after acute myocardial infarction. The prevalence and characteristics of transient myocardial ischaemia were studied in 203 patients with recent acute myocardial infarction by both early (6.4 days) and late (38 days) ambulatory monitoring of the ST segment. Transient ST segment depression was much commoner during late (32% patients) than early (14%) monitoring. Most transient ischaemia (greater than 85% episodes) was silent and 80% of patients had only silent episodes. During late monitoring painful ST depression was accompanied by greater ST depression and tended to occur at a higher heart rate. Late transient ischaemia showed a diurnal distribution, occurred at a higher initial heart rate, and was more often accompanied by a further increase in heart rate than early ischaemia. Thus in the first 2 months after myocardial infarction transient ischaemia became increasingly common and more closely associated with increased myocardial oxygen demand. Because transient ischaemic episodes during early and late ambulatory monitoring have dissimilar characteristics they may also have different pathophysiologies and prognostic implications.
Gastric infarction. We have described a patient with an acute condition of the abdomen who had infarction of the stomach and the small intestine due to atheromatous thrombus of celiac and superior mesenteric arteries. We believe this unusual simultaneous occurrence of gastric and small intestinal infarction is coincidental. The outcome of gastric infarction is frequently fatal.
Reduction of mortality, sudden death and non-fatal reinfarction with beta-adrenergic blockers in survivors of acute myocardial infarction: a new hypothesis regarding the cardioprotective action of beta-adrenergic blockade. Beta-adrenergic blockers have been shown definitely to reduce the incidence of total mortality, cardiovascular mortality, sudden death and nonfatal reinfarction in survivors of an acute myocardial infarction. The mechanisms to explain this protective action of beta blockers have never been elucidated conclusively, and include the antiarrhythmic and myocardial oxygen demand-reducing effects of the drugs. An antithrombotic mechanism has also been suggested. However, beta blockers have relatively weak antiplatelet activity, suggesting that their antithrombotic effects may be related to prevention of coronary artery plaque rupture and the subsequent propagation of an occlusive arterial thrombus rather than direct anticoagulant action. The therapeutic ability of beta blockers to attenuate the hemodynamic consequences of catecholamine surges, may protect a vulnerable atherosclerotic plaque from fracture, thereby reducing risk of coronary thrombosis, myocardial infarction and death.
Comparison of myocardial imaging with iodine-123-iodophenyl-9-methyl pentadecanoic acid and thallium-201-chloride for assessment of patients with exercise-induced myocardial ischemia. Iodine-123-iodophenyl-9-methyl-pentadecanoic acid [( 123I]MPDA) and thallium-201 (201Tl) were sequentially injected in 11 patients during exercise-induced myocardial ischemia. Simultaneous dual-energy planar images were obtained at 5 min, 3 and 5 hr. All studies were concordantly either positive (8/11) or negative (3/11) by both radionuclides. Exact agreement for segmental uptake was 93%, 94% and 94% for 5-min, 3- and 5-hr images, respectively. Exact agreement for defect reversibility by 3 and 5 hr were 95% and 92%. The initial defect contrasts and myocardial-to-lung ratios were similar by both agents but myocardial-to-liver ratio was lower by [123I]MPDA at 5 min, which became similar to 201Tl at 5 hr. Normal percent myocardial clearances of both agents were comparable and significantly higher than those in defect zones. Thus [123I]MPDA is suitable for myocardial imaging and correlates closely with 201Tl for initial postexercise myocardial uptake and defect reversibility. Defect reversibility appears to result from differential myocardial clearance from normal and ischemic regions.
Plastic bullet arterial embolization following gunshot injury to the heart. Case report and review of the literature. A plastic bullet penetrating the heart through the right ventricle embolized to the right profunda. Suture of the heart and extraction of the bullet resulted in uneventful recovery. The literature revealed 21 instances of embolization following proven heart penetration, in two cases through the right ventricle.
Laryngeal oedema from a neck haematoma. A complication of internal jugular vein cannulation. Laryngeal oedema occurred after formation of a neck haematoma after attempted internal jugular vein cannulation. This resulted in complete respiratory obstruction and respiratory arrest and it was impossible to ventilate her lungs manually or intubate her trachea. Oxygenation of the patient was only possible using transtracheal ventilation.
Laryngomalacia in children. Two hundred three (68 percent) of 297 children with laryngomalacia had associated respiratory disorders by flexible fiberoptic bronchoscopy (FFB). Associated disorders included congenital respiratory anomalies, a variety of anatomic obstructions of the upper and lower airways, and aspiration disorders. Mean age for isolated laryngomalacia (type 1) was 11.5 weeks (range, 5 weeks to 4 months) while children with laryngomalacia and associated respiratory disorders (type 2) had a mean age of 9.06 years (range, 6 weeks to 18 years). We conclude the following: (1) complete evaluation of the pediatric airways (bronchoscopy) is recommended in every symptomatic child with diagnosis of laryngomalacia confirmed by laryngoscopy; (2) type 1 laryngomalacia was more common in early infancy while type 2 laryngomalacia was associated with older age; (3) although type 2 laryngomalacia is the most common endoscopic diagnosis in our experience, the majority of cases were associated with lower airway dysfunction.
Diagnostic evaluation of syncope Syncope is a common medical problem and is caused by a wide variety of diseases ranging from physiologic derangements with few consequences to conditions that may be immediately life-threatening. Because of the large differential diagnosis, many diagnostic tests are available for its evaluation. However, a cause of syncope is not established in 38% to 47% of patients despite these tests. In those patients in whom a diagnosis can be assigned, the history and physical examination identify a potential cause in 49% to 85%. Furthermore, in 8% of additional patients, history and physical examination are suggestive of causes that need confirmation by specific tests. Routine blood tests rarely yield diagnostically helpful information. In those patients in whom a potential cause for syncope is identified, arrhythmias are diagnosed by electrocardiogram in 2% to 11% of patients, cardiac monitoring in 3% to 27% (telemetry or Holter), stress test in less than 1%, carotid massage in less than 1%, and electrophysiologic studies in less than 3%. Diagnosis of arrhythmias as a cause of syncope is problematic because symptomatic correlation during electrocardiographic monitoring is rarely found (approximately 4%), and as a result, there is no uniform agreement on diagnostic criteria for abnormalities. Similar problems exist in the use of electrophysiologic studies. Upright tilt testing and psychiatric examination may be useful in evaluation of recurrent syncope of unknown cause in patients without organic heart disease. Based on the results of recent studies, strategies for evaluation of patients with syncope are possible that utilize selective and goal-directed diagnostic testing.
Short-term memory and sentence comprehension. An investigation of a patient with crossed aphasia. The relationship between short-term memory impairment and sentence comprehension is explored in a right-handed patient with a focal temporoparietal lesion of the right hemisphere. The general clinical profile, as well as characteristics of the patient's immediate memory for word lists, suggests the occurrence of a 'mirror image' crossed aphasia. Detailed analysis of the patient's ability to repeat and to comprehend sentences, however, indicates some important differences between this case and previously reported patients with short-term memory impairment. It is suggested that these differences, which may be related to an unusual pattern of neuroanatomical organization of cognitive functions, involve symptom dissociations with implications for models of normal language/memory interactions.
Incidence and properties of renal masses and asymptomatic renal cell carcinoma detected by abdominal ultrasonography. Renal ultrasonography was performed in 45,905 adults, including 41,364 without any signs suggesting urinary tract malignancies, 1,667 with microscopic hematuria only and 2,874 with some signs of malignancy. Renal lesions were found in 355 adults (0.858%) in the asymptomatic, 39 (2.3%) in the microscopic hematuria and 75 (2.6%) in the symptomatic groups, respectively. Renal cell carcinoma was found in 35 (7.5%) lesions: 19 (5.4%) in the asymptomatic, none in the microscopic hematuria and 16 (21.3%) in the symptomatic groups. A total of 47 patients, including 12 other renal cell carcinoma patients transferred from related hospitals, was grouped into 28 without and 19 with symptoms. Primary tumor size and clinical stages were significantly smaller and lower, respectively, in the asymptomatic group than in the symptomatic group. Radical nephrectomy was performed in all but 2 asymptomatic patients. The 5-year survival rates after nephrectomy were 94.7 and 60.9% for the asymptomatic and symptomatic groups, respectively (p less than 0.01). The results indicate that ultrasonography is a useful tool to detect low stage asymptomatic renal cell carcinoma at low cost.
An evaluation of sensory changes and pain relief in trigeminal neuralgia following intracranial microvascular decompression and/or trigeminal glycerol rhizotomy. Nineteen patients with trigeminal neuralgia were treated with either trigeminal ganglion glycerolysis or glycerolysis and intracranial microvascular decompression. All had a good degree of pain relief. Of those receiving glycerol alone (group A), 50% subjectively reported a mild reduction of fine tactile sensation. A similar response was reported by those treated with both glycerol and decompression (group B). The degree of sensory loss was so mild that thermal testing was useless as a discriminatory tool. The degree of sensory loss was not greater when both surgical procedures were performed than when the less-invasive trigeminal ganglion glycerolysis alone was used.
Role of leukotriene C4 in mucosal damage caused by necrotizing agents and indomethacin in the rat stomach. Intragastric ethanol stimulates mucosal formation of leukotriene C4 in the rat stomach. The present study demonstrates that the increase in leukotriene C4 formation begins within 30 seconds and is maximal within 5 minutes, closely paralleled by the appearance of hemorrhagic lesions. Leukotriene C4 formation returns to prechallenge levels within 3 hours, although erosions still persist. Intragastric 0.2N NaOH, acidified 100 mmol/L taurocholate, 25% NaCl, or 0.6N HCl did not consistently increase leukotriene C4 formation despite severe mucosal injury. A number of sulfhydryl-containing or sulfhydryl-blocking agents as well as metals protected against mucosal damage and simultaneously prevented the stimulation of leukotriene C4 formation induced by ethanol. None of the agents increased and some virtually abolished mucosal formation of prostaglandin E2, indicating that gastroprotection can occur completely independently of the endogenous prostaglandin system. The leukotriene biosynthesis inhibitor MK-886 markedly suppressed gastric leukotriene C4 formation but did not protect against damage caused by ethanol, NaOH, NaCl, or acidified taurocholate. Oral indomethacin reduced the ex vivo formation of both prostaglandin E2 and, to a lesser extent, leukotriene C4 in the gastric mucosa, inducing a shift in the balance from protective prostaglandins to proulcerogenic leukotriene C4. Pretreatment with MK-886, however, did not significantly diminish indomethacin-induced lesions. These data suggest that leukotriene C4 is not the exclusive mediator of gastric injury caused by necrotizing agents or indomethacin. On the other hand, certain protective compounds exhibit a striking parallelism between protection and inhibition of ethanol-induced leukotriene C4 formation, suggesting that they may affect a target crucial for both mucosal injury and stimulation of 5-lipoxygenase.
Prosthetic above-knee femoropopliteal bypass for intermittent claudication. There is no consensus about the most appropriate management of the patient with intermittent claudication due to a superficial femoral artery occlusion. To evaluate the natural history of prosthetic above-knee femoropopliteal (AKFP) bypass, 200 operations for intermittent claudication were reviewed. One hundred AKFP bypasses were done with PTFE and 100 with dacron. In the 30 day postoperative period, four PTFE and three dacron grafts occluded without consequence and only one patient died. Analysis of results by the life-table method demonstrated statistically similar primary graft patency rates at five years (PTFE 65% SE +/- 6.5, dacron 57% +/- 6.2) and ten years (PTFE 31% +/- 18/9, dacron 32% +/- 13.2) (p greater than 0.10). Redo procedures (e.g., thrombectomy, angioplasty) were necessary on 21 grafts (12 PTFE, 9 dacron) and "secondary" patency rates at five years were 76% PTFE and 62% dacron; no grafts which required a redo procedure were patent at ten year follow-up. Major amputations during ten year follow-up were necessary in 16 (8%) patients; all amputations were in diabetic patients. Survival rates were 79% at five and 42% at ten years. An anticipated, the leading cause of death was cardiac related (25 patients); 28 (14%) patients underwent aortocoronary bypass during follow-up. A prosthetic AKFP bypass graft is a safe and durable operation which provides relief from the symptoms of intermittent claudication while allowing for the preservation of the saphenous vein for use later in the coronary or infrapopliteal circulations, should the need arise. These results indicate that the risk of amputation after AKFP is no greater than the natural history of untreated claudication; however, AKFP offers a significant improvement in life-style.
Intravenous immunoglobulin treatment in patients with chronic inflammatory demyelinating polyneuropathy. Clinical and laboratory characteristics associated with improvement. Of 52 patients fulfilling the criteria of chronic inflammatory demyelinating polyneuropathy, 20 (38%) did not improve after intravenous immunoglobulin treatment, two (4%) had a short-lasting improvement and subsequent infusions had no effect, nine (17%) reached a spontaneously or therapeutically induced complete remission, and 21 patients (40%) needed intermittent infusions to maintain improvement. All patients who improved initially had symptoms that significantly interfered with life-style. After treatment, 90% of these patients were independent in their daily activities. Significantly associated with improvement were disease duration of less than 1 year, progression of weakness until treatment, absence of discrepancy in weakness between arms and legs, areflexia of the arms, and slowed nerve conduction velocity of the motor median nerve. The probability of improvement if all these features are present in 93%.
Surgical management of pheochromocytoma with the use of metyrosine. Despite recommended preoperative preparation with alpha-adrenergic blockers, severe hemodynamic instability may occur during operations to resect pheochromocytoma. We combined the alpha-blocker phenoxybenzamine with the tyrosine hydroxylase inhibitor metyrosine in an attempt to better manage the hypertension of patients with pheochromocytoma undergoing surgical resection. This report reviews the cases of 25 consecutive patients undergoing surgery for known intra-abdominal pheochromocytoma. Each patient had elevated serum or urine levels of catecholamines or their metabolites. Nineteen patients were prepared before operation with phenoxybenzamine and metyrosine and six patients were given phenoxybenzamine alone. There were no significant differences in maximum, minimum, or mean blood pressure before or after tumor resection between patients who received metyrosine and those who did not. However careful review suggested that those who received metyrosine had more severe disease as judged by biochemical criteria. Study of selected patients matched for age and severity of disease suggested that the intraoperative blood pressure management of patients prepared with phenoxybenzamine and metyrosine was facilitated. In addition metyrosine-prepared patients lost less blood and required less volume replacement during surgery than did non-metyrosine-prepared patients. There were no apparent differences in postoperative fluid requirements. Although the study is not a prospective randomized trial, a retrospective review of patients managed with the combination of phenoxybenzamine and metyrosine suggests that surgery to resect pheochromocytoma can be better performed with both drugs than with phenoxybenzamine alone. The combination regimen appears to result in better blood pressure control, less blood loss, and the need for less intraoperative fluid replacement than does the traditional method of single-agent alpha-adrenergic blockade.
Lateral medullary infarction: prognosis in an unselected series. We describe the acute and long-term prognosis in 43 patients with lateral medullary infarction (LMI) collected from a population-based stroke registry from 1982 to July 1988. Mean age was 63.9 years and median time of follow-up was 33 months. In the acute phase, 5 patients (11.6%) died from respiratory and cardiovascular complications and 2 new strokes occurred, both in the posterior circulation. During follow-up, recurrent vertebrobasilar territory strokes occurred in only 2 patients (a rate of 1.9% per year). The mechanisms of stroke were vertebral artery (VA) branch occlusion, causing a medial medullary syndrome, and basilar artery thrombosis propagating from a contralateral, distal VA stenosis. In the acute phase of LMI, respiratory and cardiovascular events, presumably caused by autonomic dysfunction related to the lateral medullary lesion, are the major hazards. Recurrent posterior circulation strokes were uncommon during follow-up.
Posttachycardia T-wave changes. A 25-year-old previously healthy man presented to the emergency department with a tachydysrhythmia. After pharmacological intervention, the patient's rhythm converted to normal sinus and symmetrically inverted T-wave changes were noted. Although asymptomatic after conversion, the patient was admitted to the hospital and monitored for two days to rule out cardiac ischemia correlating with the T-wave changes. The patient was ultimately discharged in good health. A review of the emergency medical literature fails to reveal examples of post-tachycardic T-wave changes that may simulate myocardial ischemia but be of no clinical significance.
Nonorganizational religious participation among elderly black adults. This study investigated rates of participation in nonorganizational religious activities of elderly Black adults. Four indicators of participation were examined: reading religious materials, watching or listening to religious programs, prayer, and requests for prayer. Demographic, religious denomination, and health disability factors influenced participation in these behaviors. The findings were discussed for their implications for the development of a multidimensional conceptualization of religiosity.
Tightening the screw: statutory and legal supervision of interhospital patient transfers. A federal statute governing the transfer of indigent patients from Medicare-enrolled hospitals was first enacted in 1986. Review of the statutory and other legal controls over interhospital transfers is precipitated by its recent amendment and the fining of a Texas physician for transferring a high-risk obstetric patient without following the statutory guidelines. These events are part of a pattern of increasing regulation of the practice of medicine. Physicians and hospital administrators responsible for hospital transfer policies should be aware of regulatory developments. Hospitals contemplating transfer of patients must develop transfer policies that comply with governing law, including state law. A transfer policy should provide guidelines as to when a patient is "stable for transfer". Patients may not be transferred unless a physician can certify that delay attendant to transfer will not be detrimental. Furthermore, the policy should specify the procedures to be followed to effect a transfer and any documentation that the physician will have to complete.
Does percutaneous transluminal coronary angioplasty accelerate atherosclerotic lesions? Recent reports have suggested that angioplasty may cause or accelerate coronary arterial stenoses secondary to traumatic injury. Ninety-four coronary angiograms performed in a 1 yr period were reviewed in patients who had successful coronary angioplasty 6 to 30 mo (mean 10.7) prior to restudy. Restenosis was found in 43 of 140 dilated lesions (31%) and in 41 of 94 patients (44%). Thirty-three (35%) patients had new or progressive lesions outside the angioplasty site. New or progressive lesions occurred with similar frequency in the arteries that did not have angioplasty (23/155 = 15%) as in the arteries that did (13/127 = 10%; chi-square n.s.). In the arteries which underwent angioplasty, new or progressive lesions occurred as commonly proximal to the PTCA site (7/14, 50%) as distal (6/13, 46%). New or progressive lesions occurred in 29% of patients with concomitant restenosis, and 40% of those without restenosis (chi-square n.s.). No clinical, angiographic, or procedural factors distinguished patients with new and progressive lesions in target vessels from those without these lesions in target vessels. Patients with progressive lesions anywhere in the coronary tree were more likely to have had a shorter duration of anginal symptoms before angioplasty and a family history of coronary disease when compared with patients without progressive atherosclerosis. In conclusion, new and progressive lesions outside the angioplasty site occur after the procedure but appear unrelated to the restenosis process or traumatic injury by angioplasty instrumentation.