Melricflash/CW_MedAbstractsAlt huggingface dataset:
Determinants and significance of diltiazem plasma concentrations after acute myocardial infarction. The Multicenter Diltiazem Postinfarction Trial Research Group. A total of 1,975 plasma diltiazem concentrations were obtained from 1,067 patients enrolled in a multicenter secondary intervention study of diltiazem after acute myocardial infarction. To evaluate the determinants and significance of diltiazem concentrations in this patient population, we related drug concentrations to a variety of clinical variables recorded on the case history forms. Multiple linear regression analysis showed that (1) time from the last drug dose, (2) drug dose taken, (3) patient height (an index of lean body weight), and (4) patient age were important determinants of plasma concentration. For an equivalent dose, plasma diltiazem concentrations in a 75-year-old patient were about double those of a 25-year-old patient. Total weight and drug dose prescribed did not significantly affect plasma concentrations. Whereas drug concentrations were higher (p = 0.01) among patients with left-sided heart failure, they were not altered by renal dysfunction, hepatic disease or beta blockers. Diltiazem concentrations were a significant determinant of diastolic arterial pressure (p less than 10(-9), but neither systolic pressure nor heart rate were significantly related to diltiazem concentration. The overall incidence of adverse experiences was not related to drug concentrations, but the occurrence of second- and third-degree atrioventricular block in the coronary care unit and the need for a temporary pacemaker were substantially higher among patients with a drug concentration greater than 150 ng/ml (7.4 and 1.9%, respectively) than among patients with lower concentrations (2.6% for atrioventricular block, 0.3% for pacemaker; p = 0.02 for each). The risk of atrioventricular block was particularly increased by high diltiazem concentrations in the face of acute inferior infarction. These results suggest that diltiazem's pharmacologic and clinical effects in a large population are concentration-related, and that the consideration of patient size, age, and left ventricular function in selecting a diltiazem dose may allow for effective drug therapy with a reduced likelihood of adverse effects. 

Category: cardiovascular diseases
Role of prostanoids in renin-dependent and renin-independent hypertension. We investigated the role of prostanoid-mediated pressor mechanisms in setting the level of blood pressure in renin-dependent and renin-independent models of hypertension in unanesthetized rats. Intravenous administration of a blocker of thromboxane A2/prostaglandin endoperoxide receptors, SQ29548 (2 mg/kg bolus injection plus 2 mg/kg/hr for 3 hours), reduced from 162 +/- 4 to 144 +/- 5 mm Hg (p less than 0.05) the blood pressure of rats with aortic coarctation-induced hypertension at 7-14 days after coarctation when plasma renin activity is greatly increased. In contrast, treatment with SQ29548 was without effect on the blood pressure of either normotensive or hypertensive rats (i.e., aortic coarctation-induced hypertension at 90-113 days after coarctation, deoxycorticosterone-salt-induced hypertension) having normal or depressed values of plasma renin activity. The blood pressure-lowering effect of SQ29548 in the early phase of aortic coarctation-induced hypertension was positively correlated with the prevailing plasma renin activity and could not be demonstrated in hypertensive rats pretreated with indomethacin. We attribute the hypotensive effect of SQ29548 to interference with pressor mechanisms that depend on activation of thromboxane A2/prostaglandin endoperoxide receptors and suggest that such prostanoid-mediated mechanisms are operational and contribute to an increase in blood pressure in angiotensin-dependent forms of hypertension. Also prostanoid-mediated vasodepressor mechanisms are operational in the early phase of aortic coarctation-induced hypertension since the blood pressure of rats pretreated with SQ29548 was increased by the subsequent administration of indomethacin. Accordingly, the blood pressure of rats with aortic coarctation-induced hypertension is influenced by the interplay of prostanoid-mediated pressor and vasodepressor mechanisms. 

Category: cardiovascular diseases
Treatment of advanced neuroblastoma with I-131 meta-iodobenzylguanidine. From February 1986 to December 1988, 31 children with advanced pretreated neuroblastoma were treated with 131-I meta-Iodobenzylguanidine (131-MIBG). Thirteen children had been resistant to first-line therapy, three had suffered a local relapse, and fourteen had suffered a disseminated relapse without over bone marrow infiltration. One child was treated initially because of resistance to first-line therapy, and subsequently for a local relapse. A total of 72 courses of 131-MIBG was administered, with doses ranging from 2.8 to 6.0 GBq (median, 3.7 GBq). One child received five courses, two four courses, 13 three courses, four two courses, and 12 one course of 131-MIBG. The most common toxic effect was thrombocytopenia, with a platelet level of less than 50,000/cmm occurring after 19 of 60 evaluable courses. A leukocyte count less than 1000/cmm was seen only once. There were six major responses (two complete) lasting 4 to 9 months, and two minor responses lasting longer than 38 and 44 months. Responses were seen more commonly in children whose only lesion was a residual primary tumor and in children who had not been pretreated who experienced disseminated relapse. Further studies of the role of 131-I meta-Iodobenzylguanidine in treatment of neuroblastoma are needed. 

Category: neoplasms
Oral contraception in disease states. Oral contraceptives are clearly contraindicated in patients with a history of thromboembolic disease, ischemic heart attack, or cerebral stroke. Patients requiring long-term anticoagulant treatment can be treated with gonadotropin-releasing hormone analogs to prevent ovulation, because ruptured follicles can cause massive intraperitoneal bleeding. Patients with essential hypertension and severe liver diseases should also discontinue treatment 4 weeks before major elective surgery. Migraine and diabetes mellitus are regarded as relative contraindications, depending on the individual situation. Long-term diseases, such as Crohn's disease, epilepsy, and sickle cell anemia, also require individualized consultation. 

Category: nervous system diseases
Role of dipyridamole-echocardiography test in the evaluation of coronary reserve after coronary artery bypass grafting. The object of this study was to assess the usefulness of the dipyridamole-echocardiography test in the early evaluation of coronary artery bypass grafting, when the use of an exercise stress test is precluded. We studied 39 consecutive patients (37 men and two women, mean age 57.3 years) referred to our institute for elective coronary artery bypass. Five patients had single, 12 patients double, 20 patients triple vessel disease, and two had left main stem disease. Nineteen left internal mammary artery grafts, 20 sequential grafts, and 39 single vein grafts were performed. All the patients were subjected to the test before (time range 1 to 3 days) and after (time range 6 to 10 days) the operation in the absence of therapy. Dipyridamole was administered intravenously 0.56 mg/kg over 4 minutes (low dose); if no effect was apparent, an additional 0.28 mg/kg over 2 minutes (high dose) was given. During the test, blood pressure and a twelve-lead electrocardiogram were monitored. An arbitrary wall motion score was derived by dividing the left ventricle into six regions and grading from 0 to 3-normokinetic, hypokinetic, akinetic, and dyskinetic zones. Preoperatively the test was positive in 38 patients as evidenced by wall motion abnormalities (36 patients had electrocardiographic changes) and in one patient by electrocardiographic changes and chest pain; 22 tests were positive after the low dose and 17 after the high dose. Angina was present in 33 patients. Mean wall motion score was 1.64 per patient in the basal condition and 4.03 per patient after the test (p less than 0.001). After coronary bypass in three patients the test was positive at the same dosage that was used preoperatively, as shown by wall motion abnormalities (in two patients by electrocardiographic changes, as well). Four patients had symptoms. Furthermore, at 6 months' follow-up, a treadmill stress test performed in these three patients was positive for ischemia and angina. The wall motion score was 1.25 per patient in the basal condition and 1.53 per patient after the test (no significant difference). When the preoperative wall motion score obtained after dipyridamole echocardiography was compared with the postoperative score, a statistically significant difference was seen: 4.03 per patient versus 1.53 per patient (p less than 001). In eight patients we observed an improvement of basal myocardial contractility after the operation, which indicates the reversibility of wall motion abnormalities observed before coronary bypass. In conclusion our data show that the dipyridamole-echocardiography test is a suitable method for the early assessment of bypass grafting when other methods, exercise dependent, are not indicated.(ABSTRACT TRUNCATED AT 400 WORDS). 

Category: general pathological conditions
Creutzfeldt-Jakob disease in pituitary growth hormone recipients in the United States. To assess the magnitude of Creutzfeldt-Jakob disease (CJD) occurrence among recipients of pituitary-derived human growth hormone (HGH), we conducted an epidemiologic follow-up of 6284 recipients of HGH distributed through the National Hormone and Pituitary Program. Seven neuropathologically confirmed cases of CJD have occurred in this population to date: six patients with clinical CJD presented with ataxia and imbalance, rather than with altered mentation, which is the most common initial manifestation in sporadic CJD, and one patient died in the preclinical incubation state of the disease. All seven cases occurred among the nearly 700 HGH recipients who started therapy before 1970. Since only 10% of the cohort has been followed up for the 15-year average incubation interval from midpoint of HGH treatment to onset of symptoms, the great majority of potentially exposed patients have not yet attained the requisite incubation period for expression of CJD. The median duration of HGH therapy of 100 months in the CJD cases was significantly longer than 41 months for all patients starting treatment before 1970; thus, the duration of pituitary HGH therapy is a major risk factor for CJD. 

Category: general pathological conditions
Regional myocardial metabolism of high-energy phosphates during isometric exercise in patients with coronary artery disease BACKGROUND. The maintenance of cellular levels of high-energy phosphates is required for myocardial function and preservation. In animals, severe myocardial ischemia is characterized by the rapid loss of phosphocreatine and a decrease in the ratio of phosphocreatine to ATP. METHODS. To determine whether ischemic metabolic changes are detectable in humans, we recorded spatially localized phosphorus-31 nuclear-magnetic-resonance (31P NMR) spectra from the anterior myocardium before, during, and after isometric hand-grip exercise. RESULTS. The mean (+/- SD) ratio of phosphocreatine to ATP in the left ventricular wall when subjects were at rest was 1.72 +/- 0.15 in normal subjects (n = 11) and 1.59 +/- 0.31 in patients with nonischemic heart disease (n = 9), and the ratio did not change during hand-grip exercise in either group. However, in patients with coronary heart disease and ischemia due to severe stenosis (greater than or equal to 70 percent) of the left anterior descending or left main coronary arteries (n = 16), the ratio decreased from 1.45 +/- 0.31 at rest to 0.91 +/- 0.24 during exercise (P less than 0.001) and recovered to 1.27 +/- 0.38 two minutes after exercise. Only three patients with coronary heart disease had clinical symptoms of ischemia during exercise. Repeat exercise testing in five patients after revascularization yielded values of 1.60 +/- 0.20 at rest and 1.62 +/- 0.18 during exercise (P not significant), as compared with 1.51 +/- 0.19 at rest and 1.02 +/- 0.26 during exercise before revascularization (P less than 0.02). CONCLUSIONS. The decrease in the ratio of phosphocreatine to ATP during hand-grip exercise in patients with myocardial ischemia reflects a transient imbalance between oxygen supply and demand in myocardium with compromised blood flow. Exercise testing with 31P NMR is a useful method of assessing the effect of ischemia on myocardial metabolism of high-energy phosphates and of monitoring the response to treatment. 

Category: cardiovascular diseases
Detection of circulating candida enolase by immunoassay in patients with cancer and invasive candidiasis BACKGROUND. Invasive candidiasis is a major nosocomial infection that is difficult to diagnose. Few biochemically defined markers of invasive candidiasis are known. Initial findings suggested that the presence of candida enolase in the blood may be a novel marker for invasive candidiasis. METHODS. We tested 170 patients at high risk for invasive candidiasis for candida enolase antigenemia. All the patients had cancer and neutropenia. We detected antigen using a double-sandwich liposomal immunoassay for candida enolase in serially collected serum samples. Invasive candidiasis was proved by finding candida species in deep nonmucosal tissue, blood cultures, or both. Antigen testing was performed with the investigator blinded to tissue or culture diagnosis. RESULTS. Among 24 patients with proved invasive candidiasis, 149 serum samples were tested for enolase antigenemia; 80 were positive and 69 negative (sensitivity per sample, 54 percent). Multiple sampling improved the detection of antigenemia, which was found in 11 of 13 proved cases of deep tissue infection (85 percent) and in 7 of 11 proved cases of fungemia (64 percent). Specificity was 96 percent as measured against control groups including patients with mucosal colonization, bacteremia, and other deep mycoses. Antigenemia was detected in the absence of fungemia in 5 cases of deep tissue candidiasis, but was not detected in 6 cases of fungemia alone. CONCLUSIONS. Candida enolase antigenemia is a novel marker for invasive candidiasis. It may be a useful indicator of deep infection in patients with cancer and neutropenia and may complement the diagnostic usefulness of blood cultures. 

Category: neoplasms
Clonotypic analysis of anti-acetylcholine receptor antibodies from experimental autoimmune myasthenia gravis-sensitive Lewis rats and experimental autoimmune myasthenia gravis-resistant Wistar Furth rats. A single immunization of Lewis rats with purified acetylcholine receptor (AChR) emulsified in adjuvant typically stimulates the production of oligoclonal AChR-reactive antibodies (as demonstrated by IEF) dominated by the IgG2a subclass, of moderate but clonotypically heterogeneous relative Ag-binding avidity, and capable of inducing symptoms of experimental autoimmune myasthenia gravis. Although similar immunization of Wistar Furth rats produces AChR-reactive antibodies with similar characteristics of clonotypic heterogeneity, avidity, and isotype expression, no detectable signs of AChR-dependent muscle impairment is observed. This contrasts the ability to induce impaired AChR function upon the passive transfer of pre-formed Lewis anti-AChR antibodies into naive Wistar Furth rats, suggesting that disease resistance in this model is not conferred at the level of the AChR itself. Moreover, if more aggressive immunization protocols are used (i.e., multiple injections of AChR), a transient breakthrough of AChR-dependent muscle dysfunction can be induced directly in the Wistar Furth strain indicating that the potential for the production of disease-causing antibodies does exist in the Wistar Furth repertoire. IEF analysis of Wistar Furth anti-AChR antibodies has revealed that hyperimmunization results in modified antibody clonotype expression that might explain changing expression of disease symptoms; however, explanations for the apparent "resistance" of Wistar Furth rats to disease induction are likely to be complex. 

Category: nervous system diseases
An implantable neurocybernetic prosthesis system. The neurocybernetic prosthesis (Cyberonics, Inc.) is an implantable, multiprogrammable pulse generator that delivers constant current electrical signals to the vagus nerve for the purpose of reducing the frequency and/or severity of epileptic seizures. The device is implanted in a subcutaneous chest pocket just below the clavicle, similar to cardiac pacemaker placement. The stimulation signal is transmitted from the prosthesis to the vagus nerve through a stimulation lead. The prosthesis can be programmed using any IBM-compatible personal computer with programming software and a programming wand. The electrodes used in the first group of patients were found to break at an unacceptable rate. Design modifications appear to have resolved this problem. 

Category: nervous system diseases
Sinus nodal dysfunction in young patients with long QT syndrome. Although sinus bradycardia and low heart rate with exercise have been found in some patients with long QT syndrome, systematic evaluation, including intracardiac electrophysiologic (EPS) tests of sinus node function, has not been reported. Records were reviewed of 14 children and adolescents (age 3 to 16 years) with long QT syndrome (mean QTc 0.51 second) who underwent noninvasive testing and intracardiac EPS because of syncope or cardiac arrest. The resting electrocardiographic (ECG) sinus heart rate was low for age in only 1 of 13 patients, while the lowest Holter-monitored sinus heart rate was abnormal in 4 of 12. The maximum exercise heart rate was abnormally low in 6 of the 12 who underwent exercise testing. For the EPS tests, the corrected sinus node recovery time (CSNRT) was long in 8 of 14 and the sinoatrial conduction time (SACT) was long in six of the nine in whom it was calculable. When both noninvasive and EPS indices are considered, 13 of the 14 patients had some type of sinus node dysfunction. 

Category: nervous system diseases
Interpleural analgesia after thoracotomy. We examined the effects of the following variables on interpleural analgesia after thoracotomy: addition of epinephrine to local anesthetic, thoracostomy drainage, two-catheter placement, and location of catheter tips. Twenty patients were randomized to have one catheter (paravertebral tip location) or two catheters (paravertebral and lateral thoracic wall tip locations). Interpleural catheters were sutured to the parietal pleura by the surgeon at time of wound closure. Patients were then randomly assigned to receive 20 mL of 0.5% bupivacaine with 1:200,000 epinephrine through the single catheter or 10 mL of 0.5% bupivacaine with or without 1:200,000 epinephrine through each of the two catheters while supine. Bupivacaine concentrations in whole blood and in thoracostomy drainage fluid were assayed by gas chromatography. Actual content of bupivacaine in the drainage fluid was calculated. Degree of analgesia was assessed by verbal numerical pain scores over the first 4 h and opioid demand thereafter. Addition of epinephrine to bupivacaine did not influence the degree of analgesia. Approximately 30%-40% of any administered dose of bupivacaine was lost via the thoracostomy tube over a 4-h period. There was no correlation between the true initial dose (100 mg minus thoracostomy drainage) and Cmax. Use of two catheters resulted in significantly less opioid requirements after an initial 8-h period. Failure to achieve adequate interpleural analgesia in postthoracotomy patients may be related to loss of anesthetic via thoracostomy drainage, presence of extravasated blood and tissue fluid in the pleural space, and possibly sequestration and channeling of flow of local anesthetic by restricted motion of an operated lung. 

Category: general pathological conditions
Chondrosarcoma of the head and neck. Chondrosarcoma is a malignancy rarely encountered in the head and neck. In an attempt to define this tumor's characteristics and response to therapy, all cases of chondrosarcoma treated at the University of Michigan over the past 25 years were retrospectively studied. Fourteen cases originating in the nose and paranasal sinuses, mandible, temporal bone, and larynx were reviewed. Aggressive surgical resection was the mainstay of treatment, and resulted in an overall survival of 70%, with an average follow-up of 3.5 years. Survival was highest in primary temporal bone lesions, and lowest in paranasal sinus lesions. Unresectable lesions were not cured by other modalities. This study, therefore, continued to support the crucial role of wide surgical resection in the treatment of head and neck chondrosarcoma, but conservative resection, when needed to preserve important structures, has resulted in long-term survival. 

Category: neoplasms
Zollinger-Ellison syndrome. Relation to Helicobacter pylori-associated chronic gastritis and gastric acid secretion. Since Helicobacter pylori infects the gastric mucosa in most patients with chronic duodenal ulcer, infection with this organism has been implicated in the pathogenesis of this common disease. We postulated that if H. pylori is pathogenic in the usual type of duodenal ulcer, it should be less common when duodenal ulcer has another, specific etiology, such as Zollinger-Ellison syndrome. Gastric mucosa was compared from 18 patients with proven Zollinger-Ellison syndrome (17 of whom had had duodenal ulcer disease) and 18 controls with chronic duodenal ulcer without such a diagnosis. All subjects, who were matched for age and sex, had undergone elective gastric resections. Gastric tissues were stained by hematoxylin-eosin and Giemsa and were reviewed by an experienced pathologist who was unaware of the diagnosis. The frequency of H. pylori in patients with Zollinger-Ellison syndrome (8/18) was lower than in controls with duodenal ulcer (16/18; P less than 0.02). Moreover, chronic antral gastritis scores were higher in patients with duodenal ulcer (P less than 0.01). In Zollinger-Ellison syndrome, peak acid output was lower in patients positive (median 22 meq/30 min) compared to those negative for H. pylori (median 32 meq/30 min; P less than 0.02) but serum gastrin was correspondingly lower in patients positive for H. pylori (P less than 0.05). H. pylori infection appears to be more frequent when duodenal ulceration is not associated with another etiology, such as acid hypersecretion in Zollinger-Ellison syndrome. H. pylori infection in Zollinger-Ellison syndrome may also be associated with decreased gastric acid secretion. 

Category: digestive system diseases
cDNA cloning and sequencing of human fibrillarin, a conserved nucleolar protein recognized by autoimmune antisera. We have isolated a 1.1-kilobase cDNA clone that encodes human fibrillarin by screening a hepatoma library in parallel with DNA probes derived from the fibrillarin genes of Saccharomyces cerevisiae (NOP1) and Xenopus laevis. RNA blot analysis indicates that the corresponding mRNA is approximately 1300 nucleotides in length. Human fibrillarin expressed in vitro migrates on SDS gels as a 36-kDa protein that is specifically immunoprecipitated by antisera from humans with scleroderma autoimmune disease. Human fibrillarin contains an amino-terminal repetitive domain approximately 75-80 amino acids in length that is rich in glycine and arginine residues and is similar to amino-terminal domains in the yeast and Xenopus fibrillarins. The occurrence of a putative RNA-binding domain and an RNP consensus sequence within the protein is consistent with the association of fibrillarin with small nucleolar RNAs. Protein sequence alignments show that 67% of amino acids from human fibrillarin are identical to those in yeast fibrillarin and that 81% are identical to those in Xenopus fibrillarin. This identity suggests the evolutionary conservation of an important function early in the pathway for ribosome biosynthesis. 

Category: neoplasms