123rc/medical_text huggingface dataset:
Area-at-risk determination by technetium-99m-hexakis-2-methoxyisobutyl isonitrile in experimental reperfused myocardial infarction In a canine model of reperfused myocardial infarction, we tested the hypothesis that after reperfusion, technetium-99m-hexakis-2-methoxyisobutyl isonitrile (Tc-MIBI) tomographic imaging still reflects occlusion blood flow when the tracer is injected before reperfusion. Nine anesthetized dogs underwent 2 hours of coronary occlusion followed by 3 hours of reperfusion ending by being killed. Reference coronary blood flow was determined by radioactive microspheres injected during occlusion and after reperfusion. Biopsies in normal and ischemic myocardium and single photon emission computed tomography were obtained during occlusion and after reperfusion. Circumferential profiles were applied to axial slices divided into 5-degree sectors. The sectors were divided into 3 groups selected on the occlusion acquisition (normal, mildly reduced, and severely reduced) and compared with the postreperfusion acquisition. Tissular Tc-MIBI kinetics was assessed both by Tc-MIBI time-activity curves of normal and ischemic tissue obtained by biopsy and by the relative gradient between normal, ischemic, and necrotic postmortem tissue samples. In biopsy samples, Tc-MIBI content remained unchanged during occlusion and after reperfusion in normal as well as in ischemic tissue (4,662 +/- 2,237 counts/min/mg vs. 4,599 +/- 1,577 counts/min/mg in normal tissue, NS; 941 +/- 903 counts/min/mg vs. 1,087 +/- 721 counts/min/mg in ischemic tissue, NS). In postmortem tissue samples, there was a good correlation between occlusion microsphere blood flow and Tc-MIBI activity (r = 0.91). In the necrotic samples, mean normalized Tc-MIBI activity (10 +/- 17%) was slightly higher than the normalized microsphere blood flow (3 +/- 3%, p less than 0.001) but markedly lower than the normalized microsphere reperfusion blood flow (63 +/- 31%, p less than 0.001). Comparing the single photon emission computed tomographic acquisitions before and after reperfusion, Tc-MIBI activity remained unchanged in normal as well as in mildly reduced or severely reduced segments. Thus, our data are consistent with the hypothesis that Tc-MIBI traces blood flow, does not redistribute significantly despite reperfusion, and can be used for imaging the area at risk.
Blunt trauma of the abdomen in children. Abdominal trauma in children is usually due to motor vehicle accidents or falls, but child abuse is also a common cause. Injuries to the small intestine are particularly worrisome because symptoms may not appear for hours, days, or even weeks. This can cause significant difficulty for the investigator trying to determine when an injury occurred, or who may have caused it.
Acute pulmonary oedema following administration of ornithine-8-vasopressin. We report the case of a patient who developed acute pulmonary oedema following a short and uneventful surgical procedure. Among the differential diagnoses, the role of ornithine-8-vasopressin is emphasized.
The effect of doxazosin on platelet aggregation in normotensive subjects and patients with hypertension: an in vitro study. An in vitro assay was used to investigate the effects of doxazosin on the platelet aggregation induced by epinephrine, collagen, and adenosine diphosphate. Platelet-rich plasma from normotensive subjects and patients with hypertension was compared. Doxazosin produced a concentration-dependent inhibition of platelet aggregation in both groups, but significantly lower concentrations were required to inhibit platelet aggregation in plasma taken from patients with hypertension. The concentrations of doxazosin that inhibited platelet aggregation in vitro were similar to those that are used clinically to control blood pressure in patients with hypertension.
Colorectal cancer: evidence for distinct genetic categories based on proximal or distal tumor location PURPOSE: To examine studies of normal colon and colorectal cancer for evidence that the location of the primary tumor proximal or distal to the splenic flexure of the colon may determine distinct genetic categories of this disease. DATA IDENTIFICATION: Studies were identified through a manual search of journals, through MEDLINE, and through review of bibliographies in identified articles. STUDY SELECTION: Approximately 300 articles were examined. About 150 articles were excluded because tumor location was not reported or was reported in a way that did not permit correlation with results or conclusions. DATA EXTRACTION: Articles were selected either because the presentation of data permitted correlation of results with anatomic regions of the colon or because they were relevant to inherited colorectal cancer. RESULTS OF THE ANALYSIS: Differences were noted in biologic properties of proximal and distal segments of normal fetal and adult colonic epithelium and in the epidemiologic, pathologic, cytogenetic, and molecular features of proximal and distal colorectal cancer. Some differences correlated with the features of inherited colorectal cancer (proximal, nonpolyposis or distal, and polyposis forms). CONCLUSIONS: Developmental and biologic differences in proximal and distal colon may reflect differing susceptibilities to neoplastic transformation. Differences in proximal and distal colorectal cancer suggest that each may arise through different pathogenetic mechanisms. Proximal tumors appear to represent a genetically more stable form of the disease and may arise through the same mechanisms that underlie inherited nonpolyposis colon cancer. Distal tumors show evidence of greater genetic instability and may develop through the same mechanisms that underlie polyposis-associated colorectal cancer syndromes.
Multimodality preoperative treatment for advanced stage IV (MO) cancer of the head and neck. Sixty-three patients with advanced unresectable squamous cell carcinoma of the head and neck were treated with a combination of chemotherapy, radiation, and surgery. We observed a 75% response to neoadjuvant chemotherapy. The 5-year survival rate for all 63 patients was 20%, and only 3 patients were alive at 8 years. The 5-year survival rate for patients who completed the treatment plan and received chemotherapy, radiation, and surgery was 43% compared with 20% for those who had chemotherapy and radiation but refused surgery. Development of a second primary cancer was the cause of death in 62% of the patients who survived more than 24 months.
Nonpeptide angiotensin II receptor antagonists. Although the most direct way to interfere with the renin-angiotensin system (RAS) is at the level of the angiotensin II (AII) receptor, the currently available AII receptor antagonists are peptides still retaining significant agonistic properties with the obvious drawbacks of limited stability and lack of oral activity. We have characterized simple N-benzylimidazoles as weak, but selective AII receptor antagonists with a competitive mode of action. Chemical modification of these early leads led to EXP6155 and EXP6803, which show approximately 10- and 100-fold higher affinity. Oral activity was obtained for EXP7711, and in particular for EXP9654. This class of compounds displaces 3H-AII from its specific binding sites in various tissues. They competitively antagonize AII-induced responses in various in vitro and in vivo preparations, but do not influence AII-induced responses to KCl, norepinephrine, and vasopressin, nor do they affect converting enzyme or renin. In high renin models of elevated blood pressure, such as the renal hypertensive rat and sodium-depleted dog, these substances produce a sustained decrease in arterial pressure without changing heart rate after intravenous and oral (EXP7711 and EXP9654) administration. None of these compounds showed agonistic activity in any of the above test systems. In conclusion, the nonpeptide structures described herein are selective and competitive AII receptor antagonists and add another dimension to the arsenal of drugs manipulating the RAS.
Delayed pharyngoesophageal perforation: a complication of anterior spine surgery. Stabilization of the cervical spine is often accomplished via an anterior cervical approach. Bone grafts and/or plates and screws are used to achieve stabilization. Injuries to the pharynx and esophagus are known complications in anterior exposure of the cervical spine. These injuries are manifest in the early postoperative period. Reports of late perforations are very rare. We present four cases of delayed injury to the pharynx and esophagus that resulted in abscess or fistula. We postulate that graft displacement with resulting erosion was responsible for these serious complications. Postoperative odynophagia in patients who undergo anterior cervical fusion warrants evaluation of the bone graft location. Early surgical intervention and repair may decrease prolonged morbidity in these patients.
Mechanical myocardial actuation during ventricular fibrillation improves tolerance to ischemia compared with cardiopulmonary bypass. Direct mechanical ventricular actuation (DMVA) is a unique non-blood-contacting biventricular assist device that provides circulatory support during ventricular fibrillation without demonstrating adverse effects on the myocardium. The purpose of this study was to assess the preservation of myocardial energy stores and myocardial responses to ischemia after circulatory support during ventricular fibrillation with direct mechanical ventricular actuation versus cardiopulmonary bypass. Twenty adult mongrel dogs were randomized to receive circulatory support with either cardiopulmonary bypass or direct mechanical ventricular actuation. After 4 hours of ventricular fibrillation, hearts were defibrillated and left ventricular transmural biopsies were obtained. Hearts were then excised and subjected to 90 minutes of normothermic total ischemia. Serial biopsies were obtained at 15-minute intervals to determine regional depletion of high energy phosphates. The time-to-peak ischemic contracture was recorded by using needle-tipped Millar catheters placed in the left ventricular endocardium, epicardium, septum, and right ventricle. Time-to-peak ischemic contracture of the endocardium (62.6 +/- 1.4 vs. 58.8 +/- 1.0 minutes, p less than 0.05) and septum (61.1 +/- 6.9 vs. 46.9 +/- 6.2 minutes, p less than 0.004) were significantly prolonged after direct mechanical ventricular actuation versus cardiopulmonary bypass, respectively. Similar trends were noted in the epicardium and right ventricular regions; however, these differences were not statistically significant. Left ventricular adenosine triphosphate (ATP) levels were better preserved after direct mechanical ventricular actuation (22 +/- 1.5 mumols/g dry wt) compared with cardiopulmonary bypass (17 +/- 1.9 mumols/g dry wt). The depletion of left ventricular endocardium ATP during normothermic ischemia was significantly delayed after direct mechanical ventricular actuation compared with cardiopulmonary bypass.
Prevalence of spontaneous hepatofugal portal flow in liver cirrhosis. Clinical and endoscopic correlation in 228 patients. The prevalence of spontaneous reversal of flow in the portal venous system was non invasively evaluated by Doppler ultrasound in 228 patients with liver cirrhosis and portal hypertension. Reversed flow was detected in the portal vein in 7 patients (3.1%), in the splenic vein in 7 patients (3.1%), and in the superior mesenteric vein in 5 patients (2.1%), with an overall prevalence of 8.3% (19/228). This prevalence did not differ in relation to the etiology of liver cirrhosis, whereas hepatofugal flow was found in more patients classified as Child's C (15.4%) and B (12.5%) than those classified as Child's A (2.7%) (P less than 0.02) and was associated with a higher frequency of hepatic encephalopathy (21% vs. 7.2%; P less than 0.05). Endoscopic evaluation of esophageal varices did not reveal any correlation between the presence and size of varices and hepatofugal flow, whereas red signs were detected more frequently in patients with this hemodynamic pattern (42.1% vs. 24.4%; NS). The rate of previous variceal bleeding was not significantly different in patients with and without hepatofugal flow (30.8% vs. 24.4%; NS). Conversely, the prospective evaluation of 15 patients with hepatofugal flow and 29 matched patients with hepatopetal flow, derived from the group of 228 patients, followed up for a period of 12-18 months, showed that variceal bleeding occurred in 9 of 29 patients with hepatopetal flow and in none of the 15 patients with hepatofugal flow (P less than 0.02). However, no statistical difference was found in the survival rates. This study indicates that the actual prevalence of reversed flow in the portal, splenic, and superior mesenteric veins in a nonselected cirrhotic population is 8.3%. From a clinical point of view, the data suggest that this finding might be considered an important prognostic factor because, while occurring in cirrhotic patients with more severe functional impairment, it might play a protective role against the risk of bleeding.
Mucinous cystadenoma of the lung. A report of two cases with immunohistochemical and ultrastructural analysis. We describe two patients who presented with solitary pulmonary masses that consisted of unilocular cysts lined by columnar mucinous epithelium. The cysts contained copious mucus. The epithelial lining of the cysts showed foci of stratification and papillary infolding. Histologically identical lesions have previously been termed unusual mucous cysts or mucinous cystadenomas. We believe that these tumors are true neoplasms differentiating toward the respiratory epithelial mucous cell. They should be distinguished from a variety of pulmonary neoplasms including bronchoalveolar carcinoma, bronchial mucous gland adenoma, mucoepidermoid carcinoma, and metastatic adenocarcinoma.
The flail mitral valve: echocardiographic findings by precordial and transesophageal imaging and Doppler color flow mapping. To determine the echocardiographic and Doppler characteristics of mitral regurgitation associated with a flail mitral valve, precordial and transesophageal echocardiography with pulsed wave and Doppler color flow mapping was performed in 17 patients with a flail mitral valve leaflet due to ruptured chordae tendineae (Group I) and 22 patients with moderate or severe mitral regurgitation due to other causes (Group II). Echocardiograms were performed before or during cardiac surgery; cardiac catheterization was also performed in 28 patients (72%). Mitral valve disease was confirmed at cardiac surgery in all patients. By echocardiography, the presence of a flail mitral valve leaflet was defined by the presence of abnormal mitral leaflet coaptation or ruptured chordae. Using these criteria, transesophageal imaging showed a trend toward greater sensitivity and specificity than precordial imaging in the diagnosis of flail mitral valve leaflet. By Doppler color flow mapping, a flail mitral valve leaflet was also characterized by an eccentric, peripheral, circular mitral regurgitant jet that closely adhered to the walls of the left atrium. The direction of flow of the eccentric jet in the left atrium distinguished a flail anterior from a flail posterior leaflet. By transesophageal echocardiography with Doppler color flow mapping, the ratio of mitral regurgitant jet arc length to radius of curvature was significantly higher in Group I than Group II patients (5.0 +/- 2.3 versus 0.7 +/- 0.6, p less than 0.001); all of the Group I patients and none of the Group II patients had a ratio greater than 2.5.
Nocturnal faecal soiling and anal masturbation. Two cases of late onset faecal soiling as a result of anal masturbation in children who were neither mentally handicapped nor psychotic were studied. The role of soiling in aiding the young person and his family to avoid separating and maturing is highlighted. We suggest that the association of anal masturbation and resistant nocturnal soiling may be unrecognised.
Congenital tracheoesophageal fistula associated with carcinoma of the lung in an adult. A rare case of adult congenital H-type tracheoesophageal fistula was diagnosed. Subsequently, at operation, large cell, undifferentiated carcinoma of the right middle lobe with extension to the right lobe and adherence to the diaphragm was documented. The diagnosis, surgical intervention, and 4-year follow-up are presented.
Myocardial amiodarone and desethylamiodarone concentrations in patients undergoing cardiac transplantation. Myocardial amiodarone and desethylamiodarone concentrations were measured at multiple sites in the explanted heart in four patients who underwent cardiac transplantation. Patients were taking amiodarone, 200 to 400 mg/day (mean 300 +/- 115), for 88 to 428 days (mean 229 +/- 148). The mean cumulative dose was 58 +/- 21.3 g. Plasma amiodarone concentration in three subjects was 204, 312 and 419 ng/ml and desethylamiodarone concentration was 268, 513 and 880 ng/ml, respectively. Significant interindividual variability in myocardial concentrations of amiodarone and desethylamiodarone was observed (p less than 0.05). Mean myocardial amiodarone concentration ranged from 4 +/- 1.0 to 29 +/- 17.2 micrograms/g (p less than 0.05); mean desethylamiodarone concentration ranged from 22 +/- 8.8 to 141 +/- 102.5 micrograms/g (p less than 0.05). At each site, save for fat, myocardial desethylamiodarone concentration was higher than amiodarone concentration. Greater intraindividual variability was observed in myocardial desethylamiodarone compared with amiodarone concentration particularly in septal and scar tissue (p = NS). No significant relation was found between myocardial concentration and duration of treatment. In patients with significant ventricular disease, usefulness of plasma amiodarone and desethylamiodarone concentration to estimate myocardial concentration is limited by intra- and interindividual variability.
Interaction of the v-rel protein with an NF-kappa B DNA binding site. The avian reticuloendotheliosis virus T contains within its genome the oncogene rel. The expression of this gene is responsible for the induction of lymphoid tumors in birds. Recently, the rel gene was shown to be related to the p50 DNA binding subunit of the transcription factor complex NF-kappa B. Binding sites for the NF-kappa B complex are found in the enhancer regions of a number of genes, including the immunoglobulin kappa gene and the human immunodeficiency virus long terminal repeat. In this communication we identify an activity from avian reticuloendotheliosis virus T-transformed avian lymphoid cells that binds in an electrophoretic-mobility-shift assay to an NF-kappa B binding site from the kappa enhancer. This activity contains proteins immunologically related to rel, as detected by polyclonal and monoclonal antibodies directed against v-rel. In a DNA affinity precipitation assay using the NF-kappa B site from the human immunodeficiency virus long terminal repeat, v-rel and several other proteins were identified. These data suggest that oncogenic transformation by v-rel is the result of an altered pattern of gene expression.
Pancreatic secretory trypsin inhibitor stimulates the growth of rat pancreatic carcinoma cells. Pancreatic secretory trypsin inhibitor was examined for growth-promoting activity on five cell lines using standard cell culture techniques. One cell line, AR4-2J, derived from a rat pancreatic acinar cell carcinoma, responded with significantly increased incorporation of [3H]thymidine and colony formation. Pancreatic secretory trypsin inhibitor stimulated the incorporation of [3H]thymidine in liquid culture; the maximal increase was 61 +/- 10% above control (P less than 0.001) and was seen at a concentration of 10(-9) mol/L. Using a soft agarose clonogenic assay, pancreatic secretory trypsin inhibitor also consistently stimulated (3 assays) colony formation: the peak activity occurred at a concentration of 10(-10) mol/L which caused a 150 +/- 55% (mean +/- SE, P less than 0.05) increase above control. Aprotinin had no effect on the growth of AR4-2J cells and pancreatic secretory trypsin inhibitor did not bind to the epidermal growth factor receptor. AR4-2J cells were shown to produce pancreatic secretory trypsin inhibitor. The study raises the possibility that pancreatic secretory trypsin inhibitor provides autocrine stimulation of tumor cell growth.
Surgical management of exophytic chiasmatic-hypothalamic tumors of childhood. Sixteen children underwent 18 operations for radical resection of chiasmatic-hypothalamic tumors. The clinical presentation correlated with age: infants under 1 year of age presented with macrocephaly, failure to thrive, and severe visual failure; children aged 1 to 5 years predominantly had precocious puberty with mild visual deficits; and older children (greater than 5 years old) had slowly progressive loss of vision. All three infants had biologically aggressive tumors in spite of low-grade histology, and died from progressive tumor growth. Eleven of the 13 children aged 1 year or over are alive and well, without clinical or radiographic evidence of disease progression, 4 months to 4 1/2 years following surgery. Six of these patients, with a follow-up period of 10 months to 4 1/2 years (mean 27 months), have had no adjuvant therapy following radical surgical resection. The authors conclude that: 1) radical surgical resection of chiasmatic-hypothalamic tumors can be performed with minimal morbidity; 2) radical resection may delay the time to disease progression in older children and postpone the need for irradiation; 3) resection of postirradiation recurrent tumors may provide neurological improvement and long-lasting clinical remission; and 4) chiasmatic-hypothalamic tumors of infancy are aggressive neoplasms that require multimodality therapy.
Calcifications in breast biopsy specimens: discrepancies in radiologic-pathologic identification. To analyze the effectiveness and accuracy of the diagnostic process from screening mammography to final diagnosis at pathologic examination, the authors conducted a prospective study of 277 consecutive patients who underwent 291 mammographically directed biopsies of nonpalpable lesions. Of the 170 lesions that demonstrated findings consistent with calcification on preoperative mammograms and radiographs of specimens, 12 (7.1%) were not described by the pathologist as being calcified. These discrepancies were due to inadequate sampling in three cases (25%), lack of explicit description by the pathologist in four (33%), presence of oxalate crystals that required examination with polarizing lenses in two (17%), and unexplained loss of tissue probably related to processing in three (25%). Of the 121 lesions that did not demonstrate findings consistent with calcification at radiography, eight (6.6%) were described as calcified by the pathologist. The authors recommend a protocol for avoiding these discrepancies that involves performance of a more comprehensive examination of histologic sections by the pathologist, including the use of polarizing lenses, if necessary, and radiographic reexamination of paraffin-embedded tissue blocks with subsequent step sectioning by the pathologist when results are positive.
Neuropsychological performance in patients with mild multiple sclerosis. Although changes in cognitive function in patients with multiple sclerosis (MS) have been reported, these changes have been traditionally associated with the later stages of the disease. In the current study, a comprehensive neuropsychological battery was administered to MS patients (N = 86) in whom the disease progression was relatively mild and in remission and a demographically well-matched control group (N = 46). Besides the expected differences in tests of motor function, the two groups also differed on a number of cognitive tests with no motor demands. The two cognitive functions that appear impaired were learning and memory. Given that similar deficits have been found in MS patients with more severe symptoms, it is argued that changes in cognitive function can occur in the mild stages of the disease.