shukoor65/lab-rag-model huggingface dataset:
Predicting the outcomes of electrophysiologic studies of patients with unexplained syncope: preliminary validation of a derived model. PURPOSE: To develop and validate a predictive model that would allow clinicians to determine whether an electrophysiologic (EP) study is likely to result in useful diagnostic information for a patient who has unexplained syncope. PATIENTS: One hundred seventy-nine consecutive patients with unexplained syncope who underwent EP studies at two university medical centers comprised the training sample. A test sample to validate the model was made up of 138 patients from the clinical literature who had undergone EP studies for syncope. DESIGN: Retrospective analysis of patients undergoing EP studies for syncope. The data collector was blinded to the study hypothesis; the electrophysiologist assessing outcomes was blinded to clinical and historical data. Clinical predictor variables available from the history, the physical examination, electrocardiography (ECG), and Holter monitoring were analyzed via two multivariable predictive modeling strategies (ordinal logistic regression and recursive partitioning) for their abilities to predict the results of EP studies, namely tachyarrhythmic and bradyarrhythmic outcomes. These categories were further divided into full arrhythmia and borderline arrhythmia groups. RESULTS: Important outcomes were 1) sustained monomorphic ventricular tachycardia (VT) and 2) bradyarrhythmias, including sinus node and atrioventricular (AV) conducting disease. The results of the logistic regression (in this study, the superior strategy) showed that the presence of organic heart disease [odds ratio (OR) = 3.0, p less than 0.001] and frequent premature ventricular contractions on ECG (OR = 6.7, p less than 0.004) were associated with VT, while the following abnormal ECG findings were associated with bradyarrhythmias: first-degree heart block (OR = 7.9, p less than 0.001), bundle-branch block (OR = 3.0, p less than 0.02), and sinus bradycardia (OR = 3.5, p less than 0.03). Eighty-seven percent of the 31 patients with important outcomes at EP study had at least one of these clinical risk factors, while 95% of the patients with none of these risk factors had normal or nondiagnostic EP studies. In the validation sample, the presence of one or more risk factors would have correctly identified 88% of the test VT patients and 65% of the test bradyarrhythmia patients as needing EP study. CONCLUSION: These five identified predictive factors, available from the history, the physical examination, and the initial ECG, could be useful to clinicians in selecting those patients with unexplained syncope who will have a serious arrhythmia identified by EP studies.
First-pass nuclear magnetic resonance imaging studies using gadolinium-DTPA in patients with coronary artery disease. Nuclear magnetic resonance (NMR) imaging has been shown to accurately portray cardiac anatomy and function. To investigate the potential of NMR imaging for the assessment of coronary stenosis in patients with chest pain, ultrafast NMR imaging in conjunction with a T1 (longitudinal relaxation time) contrast agent was performed in 17 patients with chest pain who had undergone cardiac catheterization. These included 12 patients with significant coronary artery stenoses and 4 who underwent repeat NMR study after myocardial revascularization. Cardiac images at rest were obtained during rapid intravenous injection of gadolinium-DTPA (0.04 mM/kg). Electrocardiographic-gated images were acquired over 380 ms, with repetitive images obtained every 3 to 4 s. After contrast injection, there was pronounced signal enhancement in the right ventricular cavity, followed by enhancement in the left ventricular cavity and myocardium. Regional myocardium perfused by a diseased vessel demonstrated a lower peak signal intensity (p = 0.001) and lower rate of signal increase (p = 0.001) than did myocardium perfused by coronary arteries without stenosis. Repeat NMR study after revascularization showed an increase in peak signal intensity (p less than 0.002). These results demonstrate the clinical potential of dynamic gadolinium-DTPA-enhanced NMR imaging for the assessment of coronary artery disease in patients with chest pain. In combination with anatomic and functional NMR imaging, this technique has the potential to provide a comprehensive noninvasive cardiac evaluation of patients with suspected coronary artery disease.
Plasma atrial natriuretic peptide in young normotensive subjects with a family history of hypertension and in young hypertensive patients. Plasma atrial natriuretic peptide (ANP) behavior was evaluated in 26 untreated essential hypertensives, 21 normotensives, and 20 normotensives with hypertensive heredity under normal sodium intake (120 mEq of Na+/day). All subjects were men, mean age 22.1 +/- 1.9 years. Plasma ANP was evaluated by radioimmunoassay on samples collected in supine position upon waking and again after 1 h of orthostatism. Resulting data showed that ANP in hypertensives (supine = 44.5 +/- 19.4 pg/mL, orthostatism = 24.1 +/- 11.6 pg/mL) was at higher levels than in controls (supine = 38.3 +/- 19.4 pg/mL, orthostatism = 19.9 +/- 10.6 pg/mL) or in normotensives with hypertensive heredity (supine = 42.1 +/- 16.8 pg/mL, orthostatism = 23.2 +/- 10.8 pg/mL). Mean ANP level was higher in the latter group than in the control group (supine = +9%; orthostatism = +14.2%). In conclusion, plasma ANP is raised in young essential hypertensives, resulting in slightly elevated levels in normotensives with hypertensive heredity.
Birthweight ratio revisited. In order to test the hypothesis suggested in a recent report that the birthweight ratio might be a useful predictor of several important clinical outcome measures in babies of less than 31 weeks' gestation, we examined the association between the birthweight ratio and aspects of both short and long term outcome in 436 Leeds babies of less than 31 weeks' gestation. Unlike the report, and contrary to what we had expected, we were unable to find any significant association between birthweight ratio and length of time on the ventilator, mortality, neurological outcome, or intellectual outcome.
Dideoxyinosine in children with symptomatic human immunodeficiency virus infection. BACKGROUND. 2',3'-Dideoxyinosine (ddl) is a dideoxynucleoside with potent activity in vitro against the human immunodeficiency virus (HIV). In initial clinical trials in adults, ddl showed evidence of antiretroviral activity with little hematologic toxicity. METHODS. We conducted a phase I-II study in 43 children with symptomatic (CDC class P-2) HIV infection. Of these children, 16 (median age, 10 years) had previously received zidovudine, and 27 (median age, 2.6 years) had not. ddl was administered orally in three divided doses totalling 60, 120, 180, 360, or 540 mg per square meter of body-surface area per day for 24 weeks. Eight of the 43 patients did not complete 24 weeks of ddl: 6 died, 1 was withdrawn because of progressive disease, and the other because of toxicity. RESULTS. After oral administration, ddl was rapidly absorbed, although its bioavailability varied greatly among patients. Pancreatitis developed in two children, one receiving ddl at each of the two highest doses. The median CD4 cell count in 38 patients with paired counts increased from 0.218 x 10(9) per liter (218 per cubic millimeter) at base line to 0.327 x 10(9) per liter (327 per cubic millimeter) after 20 to 24 weeks (P = 0.001). Those with CD4 cell counts above 0.1 x 10(9) per liter (100 per cubic millimeter) at base line were significantly more likely to improve in this respect. The median levels of p24 antigen (in 27 patients with detectable levels at entry) declined from 272 pg per milliliter at base line to 77 pg per milliliter at 20 to 24 weeks (P = 0.005). The plasma concentration of ddl correlated significantly with both the degree of decline in the p24 antigen and the degree of improvement in IQ score. Improvement in clinical and immunologic measures occurred in both the previously untreated patients and in those who had been treated with zidovudine. CONCLUSIONS. Dideoxyinosine was well tolerated and showed promising antiretroviral activity in HIV-infected children. The correlation between the clinical response and the plasma concentration of ddl indicates that bioavailability is an important consideration in the use of ddl to treat HIV infection and that individualized pharmacokinetic monitoring and dose adjustment may be important for optimal activity.
Optic nerve sheath decompression for the treatment of progressive nonarteritic ischemic optic neuropathy. We performed optic nerve sheath decompression on four patients (five eyes) with visual loss secondary to nonarteritic anterior ischemic optic neuropathy. Four of the five eyes had marked improvement in visual function after the operation. Optic nerve sheath decompression is an effective treatment for patients with nonarteritic ischemic optic neuropathy and progressive visual loss.
Resection of a granular cell tumor at the hepatic confluence. A precarious location for a benign tumor. Granular cell tumors are lesions that account for less than 10 per cent of benign biliary tumors and only 1 per cent occur in the biliary tract. Since the first description, 45 other cases have been described to which we add a case. In reviewing the literature, a striking predominance in black females is evident. The most frequent location of these tumors in the biliary tree appears to be the common bile duct (50%), followed by the cystic duct (37%), the hepatic ducts (15%), and the gallbladder (4%). Most patients have been treated with resection followed by restoration of biliary continuity using biliary enteric diversion. In the case presented, the tumor was located at the hepatic confluence with extension into the hepatic substance requiring segmental duct cholangiojejunostomy after resection. This resulted in fulminant sepsis and death despite adequate preoperative biliary decompression and the lack of signs or symptoms of infected bile. Alternative forms of management in the treatment of this benign condition at this location are discussed.
Advantages of an immunohistochemical estrogen receptor assay. Immunohistochemical and biochemical assays for estrogen and progesterone receptors were done on 20 breast carcinomas, and results were correlated with various histologic features. The slide-based immunohistochemical technique demonstrated several distinct advantages relative to the tissue homogenization required by the traditional biochemical assay. With the use of frozen tissue sections, the immunohistochemical technique permitted direct visualization of antireceptor binding to tumor cells. Receptor staining of reactive stroma, necrotic tumor, and intermingled benign parenchyma was easily distinguished from receptor staining of the actual carcinoma. This separation is not possible with the biochemical assay. In addition, in situ and invasive components and different morphologic subtypes were evaluated independently. Receptor content of the most aggressive portion of the neoplasm is likely to have the greatest clinical relevance and prognostic significance. Careful correlation of histochemical scores with biochemical assay concentrations is needed to permit the application of this technique to patients entering cancer treatment protocols.
Use of adenosine echocardiography for diagnosis of coronary artery disease. Two-dimensional echocardiography combined with exercise is sensitive and specific in the detection of coronary artery disease (CAD) by demonstrating transient abnormalities in wall motion. Frequently, however, patients cannot achieve maximal exercise because of various factors. Pharmacologic stress testing with intravenous adenosine was evaluated as a means of detecting CAD in a noninvasive manner. Patients with suspected CAD underwent echocardiographic imaging and simultaneous thallium 201 single-photon emission computed tomography during the intravenous administration of 140 micrograms/kg/min of adenosine. An increase in heart rate, decrease in blood pressure, and increase in double product were observed during adenosine administration. Initial observations revealed that wall motion abnormalities were induced by adenosine in areas of perfusion defects. The adenosine infusion was well tolerated, and symptoms disappeared within 1 to 2 minutes after termination of the infusion. Therefore preliminary observations suggest that adenosine echocardiography appears to be useful in the assessment of CAD.
Treatment of pancreatic pseudocysts with octreotide. Pancreatic pseudocysts are a common and painful complication of chronic pancreatitis. Seven patients (six male, one female; mean age 49.9 years) with chronic pancreatitis complicated by pseudocysts and persistent pain were treated with the pancreatic anti-secretory drug octreotide for 2 weeks. Octreotide caused no notable changes in the size of the pseudocysts of three patients. In the remaining four patients, the pseudocysts decreased in size by a mean of 42% (range 29-52%), and pain disappeared completely. These findings suggest a role for octreotide in the treatment of pancreatic pseudocysts.
An open label study of oral transmucosal fentanyl citrate (OTFC) for the treatment of breakthrough cancer pain. Ten patients with advanced cancer and breakthrough pain between the ages of 39 and 78 received oral transmucosal fentanyl citrate (10-15 micrograms/kg) 4 or 5 times each over 2 days (42 total administrations) in an open study. Baseline vital sign and rating scale results did not vary over administrations, except for heart rate which showed an 8 beats/min decrease over 4 administrations. Heart rate and oxygen saturation did not vary significantly over 120 min of evaluation, and minimal changes in blood pressure and respiration rate were found. Significant reduction in pain scores as measured by a pain descriptive scale, the McGill-Melzack scale, and a numeric (VAS) scale were seen at all evaluations from 5 to 120 min. Average time to onset of pain relief was 9.5 min after administration. Wellbeing was significantly increased at all evaluations. Activity level as recorded by the investigator was significantly reduced from 10 to 30 min after administration, however, activity level as reported by the patient was significantly increased at 5 min and from 60 to 120 min after OTFC administration. There were no significant adverse effects.
Influence of calcium administration on the short-term hemodynamic and anti-ischemic effects of nifedipine. This prospective study investigated whether pretreatment with intravenously administered calcium would influence the effect of nifedipine on rest hemodynamics and treadmill performance in patients with ischemic heart disease. Seventeen patients were studied after undergoing a qualifying treadmill exercise test that revealed ST segment depression indicative of ischemic heart disease. Study subjects performed three additional treadmill tests as part of the protocol. One treadmill test was obtained from each patient to provide baseline measurements without a preceding intravenous infusion and in the absence of all antianginal drugs including nifedipine; two additional exercise tests were preceded by an infusion and 10 mg of bite-and-swallow nifedipine. The infusions, administered in a randomized, double-blind, crossover fashion, consisted of either 10 ml of 10% calcium chloride (13.6 mEq) in 50 ml of 5% dextrose in water or 5% dextrose in water alone. Rest systolic blood pressure (134 +/- 4.6 mm Hg) was unchanged after placebo infusion (135 +/- 4.6 mm Hg) but decreased to 124 +/- 4.1 mm Hg (p less than 0.01) 25 min after nifedipine administration. Rest systolic blood pressure increased after calcium infusion (from 139 +/- 4.3 to 148 +/- 4.8 mm Hg, p less than 0.01) and then decreased significantly 25 min after nifedipine administration to 135 +/- 4.2 mm Hg (p less than 0.01). Despite a decrease at the time of peak nifedipine effect after either infusion, systolic blood pressure was significantly lower after administration of nifedipine alone than after administration of calcium and nifedipine (124 +/- 4.1 vs. 135 +/- 4.2 mm Hg, p less than 0.01).
Neurophysiologic assessment of the anal sphincters. One hundred twenty consecutive patients with either fecal incontinence (60 patients), chronic constipation (41 patients), or idiopathic intractable pelvic pain (19 patients) were prospectively assessed. Patients underwent concentric needle electromyography (EMG), bilateral pudendal nerve terminal motor latency evaluation, anorectal manometry, and cinedefecography. The most common EMG finding in patients with fecal incontinence was decreased recruitment of motor units with squeezing and polyphasic motor unit potentials; these are consistent with an injury pattern. The most common EMG finding in the constipated patients was paradoxical puborectalis contraction. This latter abnormality was also a frequent finding in patients with rectal pain, as was prolongation of pudendal nerve latency. Paradoxical puborectalis contraction was diagnosed more frequently with EMG than with cinedefecography. Inter-examination correlation was best in the incontinent group between EMG and manometry. Cinedefecography had poor correlation with EMG in all patient groups but was valuable in the detection of additional pathology such as rectoanal intussusception and anterior rectocele. Electromyography including pudendal nerve terminal motor latency assessment is a valuable adjunct in the evaluation of disorders of evacuation. The information it yields is complementary to that offered by more routine physiologic examinations.
Prenatal diagnosis of the neurofibromatoses. This article reviews the application of genetic linkage analysis to molecular prenatal diagnosis using the neurofibromatoses as an example. The clinical manifestations and diagnostic criteria for these diseases are reviewed first, followed by a brief description of the principles underlying genetic linkage analysis, the detection of DNA polymorphisms and their application to the cloning of the NF1 gene. The last two sections review the molecular diagnosis and some of the problems in prenatal genetic counseling for NF1.
Ventriculoatrial intervals during narrow complex reentrant tachycardia in children. Ventriculoatrial (VA) intervals during narrow complex tachycardia were measured in a pediatric population. The VA intervals were similar to those in adults but were slightly shorter. In the pediatric subjects values less than 60 msec excluded the participation of an accessory pathway in the tachycardia circuit. Three out of 11 patients with atrioventricular nodal reentrant tachycardia (AVNRT) had VA values greater than or equal to 70 msec, while 5 of 28 patients with orthodromic reciprocating tachycardia (ORT) had values less than or equal to 70 msec. Using a cut-off value of 70 msec as the sole criteria to distinguish between ORT and AVNRT could lead to errors in classification of the underlying mechanism of the tachycardia.
A familial coincidence of pseudotumor cerebri and communicating hydrocephalus. A family in which the mother and two of four daughters had a diagnosis of pseudotumor cerebri and one son developed communicating hydrocephalus is described. The other two daughters both have a long history of headaches but no signs of intracranial hypertension. The argument is advanced that there exists a defect of cerebrospinal fluid absorption common to pseudotumor cerebri and communicating hydrocephalus.
Physical activity and reduced occurrence of non-insulin-dependent diabetes mellitus BACKGROUND. Physical activity is recommended by physicians to patients with non-insulin-dependent diabetes mellitus (NIDDM), because it increases sensitivity to insulin. Whether physical activity is effective in preventing this disease is not known. METHODS. We used questionnaires to examine patterns of physical activity and other personal characteristics in relation to the subsequent development of NIDDM in 5990 male alumni of the University of Pennsylvania. The disease developed in a total of 202 men during 98,524 man-years of follow-up from 1962 to 1976. RESULTS. Leisure-time physical activity, expressed in kilocalories expended per week in walking, stair climbing, and sports, was inversely related to the development of NIDDM. The incidence rates declined as energy expenditure increased from less than 500 kcal to 3500 kcal. For each 500-kcal increment in energy expenditure, the age-adjusted risk of NIDDM was reduced by 6 percent (relative risk, 0.94; 95 percent confidence interval, 0.90 to 0.98). This association remained the same when the data were adjusted for obesity, hypertension, and a parental history of diabetes. The association was weaker when we considered weight gain between the time of college attendance and 1962 (relative risk, 0.95; 95 percent confidence interval, 0.90 to 1.00). The protective effect of physical activity was strongest in persons at highest risk for NIDDM, defined as those with a high body-mass index, a history of hypertension, or a parental history of diabetes. These factors, in addition to weight gain since college, were also independent predictors of the disease. CONCLUSIONS. Increased physical activity is effective in preventing NIDDM, and the protective benefit is especially pronounced in persons at the highest risk for the disease.
Isolation of a human DNA sequence which spans the fragile X. To identify the sequences involved in the expression of the fragile X and to characterize the molecular basis of the genetic lesion, we have constructed yeast artificial chromosomes (YACs) containing human DNA and have screened them with cloned DNA probes which map close to the fragile site at Xq27.3. We have isolated and partly characterized a YAC containing approximately 270 kb of human DNA from an X chromosome which expresses the fragile X. This sequence in a yeast artificial ring chromosome, XTY26, hybridizes to the two closest DNA markers, VK16 and Do33, which flank the fragile site. The human DNA sequence in XTY26 also spans the fragile site on chromosome in situ hybridization. When a restriction map of XTY26, derived by using infrequently cutting restriction enzymes, is compared with similar YAC maps derived from non-fragile-X patients, no large-scale differences are observed. This YAC, XTY26, may enable (a) the fragile site to be fully characterized at the molecular level and (b) the pathogenetic basis of the fragile-X syndrome to be determined.
Antihypertensive effect of isradipine on blood pressure at rest and during exercise. After three months of treatment with isradipine, 20 patients with mild hypertension had reduced their resting blood pressure (BP) from 157/103 to 132/85 mm Hg and their BP during isometric exercise from 192/124 to 166/105 mm Hg. The isradipine dose necessary to normalize BP (both at rest and post-exercise) was 1.25 mg twice daily (2 x 1/2 tablet) in 50% of patients and 2.5 mg twice daily (2 x 1 tablet) in 25%. In the remaining 25% of patients, isradipine was combined with 1 mg/day bopindolol. There were virtually no accompanying side effects; in particular, reflex tachycardia was negligible or absent. It is concluded that isradipine is a reliable antihypertensive treatment in mild-to-moderate hypertension.