shukoor65/lab-rag-model huggingface dataset:
Copper deficiency in a genetically hypertensive cardiomyopathic rat: electrocardiogram, functional and ultrastructural aspects. The effect of copper deficiency on cardiac function and structure was studied in a strain of rats (SHHS/Mcc-cp) known to develop cardiac failure as adults. Restriction of dietary copper (less than or equal to 1 mg/kg vs. 6 mg/kg in adequate diets) at weaning in both sexes for a 6-wk period produced cardiac hypertrophy. Male rats developed more severe copper-deficiency symptoms than their female counterparts. In both sexes of copper-deficient rats, there was an increase in cardiac length, width, free ventricular wall thickness and septum thickness. Electrocardiographic tracings revealed greater QRS height among male copper-deficient rats. Heart rate also was substantially reduced in this group. The increased volume of myocardium occupied by mitochondria in the copper-deficient male rats might result in increased electrical resistance that would increase the QRS height; hypertrophy or anemia also could be contributory. Some male copper-deficient rats had prolongation of the QRS in a bundle branch block pattern. Maximal rates of rise and fall for left ventricular pressure were reduced in male copper-deficient rats. The gross histology indicated that this type of heart failure was more concentric than eccentric. The copper-deficient male rat may serve as a useful model for studying the concentric cardiac hypertrophy that occurs in humans.
Giant, human immunodeficiency virus-related ulcers in the esophagus. Human immunodeficiency virus (HIV) infection of the esophagus has recently been implicated as a cause of giant esophageal ulcers in HIV-positive patients with odynophagia. The authors examined four patients in whom esophagograms (one single-contrast and three double-contrast studies) revealed giant, HIV-related ulcers indistinguishable from those of cytomegalovirus (CMV) esophagitis. All four patients had severe odynophagia, one had an associated maculopapular rash, and two became HIV-positive at approximately the time of clinical presentation. In all patients, biopsy samples, brushings, and cultures obtained with endoscopy were negative for CMV or herpes simplex. One patient had positive brushings for candidiasis, but this may have resulted from fungal superinfection of the ulcer. Two patients were treated with orally administered steroids, and all four had swift clinical improvement; symptoms disappeared during an average period of 8.3 days from presentation. HIV-related esophageal ulcers should be distinguished from CMV ulcers, so that appropriate treatment can be initiated in these patients.
Tensile properties of the human femur-anterior cruciate ligament-tibia complex. The effects of specimen age and orientation. The structural properties of 27 pairs of human cadaver knees were evaluated. Specimens were equally divided into three groups of nine pairs each based on age: younger (22 to 35 years), middle (40 to 50 years), and older (60 to 97 years). Anterior-posterior displacement tests with the intact knee at 30 degrees and 90 degrees of flexion revealed a significant effect of knee flexion angle, but not of specimen age. Tensile tests of the femur-ACL-tibia complex were performed at 30 degrees of knee flexion with the ACL aligned vertically along the direction of applied tensile load. One knee from each pair was oriented anatomically (anatomical orientation), and the contralateral knee was oriented with the tibia aligned vertically (tibial orientation). Structural properties of the femur-ACL-tibia complex, as represented by the linear stiffness, ultimate load, and energy absorbed, were found to decrease significantly with specimen age and were also found to have higher values in specimens tested in the anatomical orientation. In the younger specimens, linear stiffness (242 +/- 28 N/mm) and ultimate load (2160 +/- 157 N) values found when the femur-ACL-tibia complex was tested in the anatomical orientation were higher than those reported previously in the literature. These values provide new baseline data for the design and selection of grafts for ACL replacement in an attempt to reproduce normal knee kinematics.
Stage IIB osteogenic sarcoma. Two hundred seventy-one consecutive patients treated from 1976 through 1986 were reviewed to estimate long-term survival. Disease-free survival for the entire cohort was 77% at five years and 74% at ten years. Humeral lesions had the best probability of survival (84% at ten years), followed by tibial lesions (81%) and femoral lesions (67%). Histologic response to preoperative chemotherapy was the strongest predictor of outcome. Those with little response had a survival estimate of 54% at ten years as compared to 68% for partial responders and approximately 90% for complete responders. Local recurrence was seen in 6.6% and was associated with an adverse effect on survival. Only two of the 18 patients with local recurrence have been rendered long-term disease-free survivors.
Liver diseases unique to pregnancy. Severe liver diseases occur in less than 0.1% of pregnancies. Accurate diagnosis and appropriate therapy are essential to the health and survival of both the mother and fetus. Because of their low incidence and the fact that most pregnant women are cared for primarily by their obstetricians, gastroenterologists only infrequently encounter these diseases. This review is intended to update the practicing gastroenterologist on the complex spectrum of liver diseases unique to pregnancy.
A comparison of the analgesic and respiratory effects of epidural nalbuphine or morphine in postthoracotomy patients. This randomized, double-blind study compared the analgesic and respiratory effects of lumbar epidural morphine 5 mg, nalbuphine 10 mg, and nalbuphine 20 mg in repeated doses in patients after thoracotomy; the first dose was administered intraoperatively. Pre-and postoperative monitoring included continuous pulse oximetry, respiratory inductance plethysmography, and repeated arterial blood gas analysis. Postoperatively, visual analogue pain scores, somnolence scores, respiratory rate, and arterial blood gases were determined for 16 h. Preoperatively, episodes of apnea were common during sleep but were not associated with low hemoglobin oxygen saturation or increased arterial carbon dioxide tension (PaCO2). During sleep, some otherwise normal patients had increased PaCO2, and 2 of 15 patients had episodes of hemoglobin oxygen saturation of less than 90%. Postoperatively, 1 and 2 h after arrival in the recovery room, patients who received morphine had lower pain scores than did those who received nalbuphine 10 or 20 mg (P less than 0.05). All 6 patients who received morphine had satisfactory analgesia. Two of 4 patients who received nalbuphine 10 mg and all 5 who received nalbuphine 20 mg were withdrawn from the study because of inadequate analgesia (morphine vs. nalbuphine 10 mg, not significant; morphine vs. nalbuphine 20 mg, P less than 0.01). Two patients who received morphine had persistently increased PaCO2 postoperatively. Two patients who received morphine had episodes of apnea and slow respiratory rate, which were most frequent 6 h after arrival in the recovery room. We conclude that lumbar epidural nalbuphine does not provide adequate analgesia after thoracotomy.
Dipeptidyl aminopeptidase IV staining of cytologic preparations to distinguish benign from malignant thyroid diseases. Staining for dipeptidyl aminopeptidase IV (DAP IV [EC: 3.4.14.5]) activity was applied to aspiration biopsy specimens or imprint preparations of surgical biopsy specimens from thyroid tumors. Material was obtained from 55 patients with histologically proven thyroid diseases: 9 with papillary carcinoma, 5 with follicular carcinoma, 11 with follicular adenoma, 13 with adenomatous goiter, 8 with Hashimoto's thyroiditis, and 9 with other benign conditions. Most tumor cells, follicular lumina in cell clusters, and intranuclear inclusions were strongly positive for DAP IV in all examples of papillary or follicular carcinoma. In contrast, only a few epithelial cells were labeled for DAP IV in follicular adenoma and adenomatous goiter. Some Hurthle cells in Hashimoto's thyroiditis also were positive for DAP IV. When a DAP IV scoring system based on the percentage of positive cells and staining intensity was used, all benign tissues except one (from a follicular adenoma) were found to have extremely low scores. These results indicate that staining for DAP IV activity is a simple but useful tool to aid in distinguishing benign from malignant thyroid neoplasms.
The performance of two tympanic thermometers in a pediatric emergency department. In a prospective, unblinded, controlled study, 303 children underwent comparison of rectal (RT) and right-sided tympanic membrane (TMT) temperatures. Digital electronic thermometers were used for RT, while two different infrared detection devices assessed TMT. The performance of TMT devices were compared using correlation with RT, fever detection, and ease of use. Correlation between RT and the two devices was good, r = 0.70 and r = 0.69, with little influence of patient age on performance. Using receiver operating characteristics curves to assess fever screening. Thermoscan performed somewhat better than First Temp. Staff rated the Thermoscan as significantly easier to use.
Gene mapping in the idiopathic generalized epilepsies: juvenile myoclonic epilepsy, childhood absence epilepsy, epilepsy with grand mal seizures, and early childhood myoclonic epilepsy. Idiopathic generalized epilepsies, i.e., juvenile myoclonic epilepsy (JME), childhood absence epilepsy, and epilepsy with grand mal [generalized tonic-clonic seizures (GTCS)], are the most common genetic epilepsies. Linkage studies using Bf, HLA serologic, and DNA markers by three independent investigators, one from Los Angeles and two from Berlin, have localized the JME locus to the short arm of chromosome 6 (6p). Because members of the same JME family have the same JME phenotype of childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or early childhood myoclonic epilepsy (ECME), our observations give evidence for a single-locus etiology in 6p for JME and for at least some of the childhood absence seizures, epilepsy with grand mal (GTCS) seizures, and ECME. Studies should now address whether locus heterogeneity exists within childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or ECME. Markers linked to JME (Bf, HLA serologic, and DNA markers in the DQ region) can be used to resolve etiologic heterogeneity. Using such markers, both linked and unlinked forms of phenotypes that are clinically indistinguishable may be detected and provide evidence for etiologic heterogeneity. Studies should also concentrate on narrowing the JME locus to 2 to 3 cm by screening families with recombinant events using RFLPs, candidate genes, and new expressed sequences on chromosome 6.
Protection against infarction afforded by preconditioning is mediated by A1 adenosine receptors in rabbit heart. BACKGROUND. Preconditioning (5 minutes of ischemia followed by 10 minutes of recovery) renders the heart very resistant to infarction from subsequent ischemia. This study tests whether adenosine receptors might mediate preconditioning protection. METHODS AND RESULTS. We examined the effect on infarct size of pretreatment with either of two adenosine receptor antagonists in both control and preconditioned in situ rabbit hearts. Hearts underwent 30 minutes of regional ischemia plus 3 hours of reperfusion, and infarct size was measured with tetrazolium. Infarct size averaged 39% of the zone at risk in controls but only 8% in preconditioned hearts. Preconditioned and nonpreconditioned hearts receiving either blocker had infarcts not different in size from the controls. A 5-minute intracoronary infusion of adenosine was as effective as 5 minutes of ischemia in protecting parabiotically perfused isolated hearts against infarction from a 45-minute ischemic insult. Similarly, intracoronary infusion of N6-1-(phenyl-2R-isopropyl)adenosine, an A1-selective adenosine receptor agonist, at a dose that delayed conduction but did not dilate the coronary vessels, also limited infarct size. The protection disappeared when we reduced the coronary concentration of drug by intravenous infusion of adenosine, indicating that cardiac rather than peripheral receptors were involved in the protection. CONCLUSIONS. We conclude that adenosine released during the preconditioning occlusion stimulates cardiac A1 receptors, which leaves the heart protected against infarction even after the adenosine has been withdrawn.
A CD18 monoclonal antibody increases the incidence and severity of subcutaneous abscess formation after high-dose Staphylococcus aureus injection in rabbits. Monoclonal antibody (MAb) 60.3 blocks CD18-dependent polymorphonuclear neutrophil adherence to endothelium and has been shown to be of benefit in preventing tissue injury in a variety of inflammatory conditions. However, concern exists that interference with normal polymorphonuclear neutrophil host-defense functions may increase susceptibility to bacterial infection. We compared the development of subcutaneous Staphylococcus aureus abscesses in rabbits pretreated with MAb 60.3 to those pretreated with saline placebo. Bacterial inoculation with 10(6) or 10(7) colony-forming units (CFU) did not result in abscess formation in either control or antibody-treated groups. However, inoculation with 10(8) CFU resulted in more frequent and larger abscesses in antibody-treated rabbits than in controls. Abscess incidence was similar for inoculation with 10(9) CFU, although antibody-treated rabbits developed larger abscesses than did controls. The difference in abscess development is due to delayed leukocyte migration into inoculated tissue. The results of these experiments suggest that subjects treated with MAb 60.3 and exposed to massive S. aureus inocula may be at serious risk of infection. However, despite inhibited leukocyte adhesion, inocula of up to 10(7) CFU were well tolerated in this model. Whether these findings are clinically important remains to be determined, although exposure to bacterial concentrations of 10(8) CFU or greater occurs only rarely in clinical practice.
The frequency and significance of ECG changes after transurethral prostate resection. Although many clinicians routinely recommend a base-line preoperative electrocardiogram (ECG) and obtain frequent postoperative ECGs to screen for myocardial infarction or ischemia, the diagnostic utility of screening perioperative ECGs is unknown. The present analysis evaluates the sensitivity and specificity of the perioperative ECG and examines its value as a predictor of early postoperative cardiac events and outcomes during the postoperative year. ECGs obtained preoperatively and on the first 3 postoperative days in 206 men undergoing transurethral prostate resection were analyzed using the Minnesota Code. The occurrence of cardiac events during the operative stay was assessed by measurement of the cardiospecific MB creatine kinase isoenzyme on the first 3 postoperative days and review of the entire clinical course. Twenty-one percent of patients developed postoperative ECG changes, mostly involving the T wave; none had cardiac symptoms or sustained creatine kinase MB elevation. Changes were not significantly more common in men known to have coronary disease. The single patient who had a perioperative myocardial infarction confirmed by enzymes had no codable ECG changes. The specificity of any ECG change for perioperative infarction was 78%; of ST segment changes only, 95%. Only one of the patients (2%) who had postoperative ECG changes had a cardiac event in the year after surgery. Routine perioperative ECGs is of little diagnostic/predictive utility in situations in which the incidence of perioperative myocardial infarction is low.
MR imaging of synovial sarcoma. The MR imaging findings in 12 cases of synovial sarcoma are illustrated. The MR appearance most indicative of the tumor is an inhomogeneous septated mass with infiltrative margins located close to a joint, a tendon, or bursae, especially if soft-tissue calcification can be seen on CT scans or plain radiographs.
Hormone replacement therapy and coronary heart disease. Proper use of postmenopausal hormone replacement has been the subject of debate for decades. Prevailing medical opinion has swung between enthusiastic endorsement and extreme caution. The wave of optimism over estrogen's beneficial effects on menopausal symptoms and skeletal health was temporarily set back by the evidence that linked estrogen to endometrial cancer. Once studies showed that progestogen cotherapy could protect against this adverse effect, physicians were again encouraged to prescribe hormone replacement. Since 1980, increasing epidemiologic and experimental evidence has suggested a hitherto unappreciated and immense CHD health benefit from use of postmenopausal estrogen therapy. Although addition of progestogen may offset the cardiovascular benefits of estrogen slightly, its use is reasonable and practical. No woman need be subjected to unopposed estrogen's carcinogenic effects on her endometrium. Based on available evidence, hormone replacement therapy, appropriately administered, is both safe and beneficial. Unfortunately, there is no single way to prescribe it. The treating physician must make a series of best judgments. Practically speaking, this entails, in each case, finding the form of therapy that is acceptable to the patient and that provides the greatest health benefits with the least likelihood of adverse affects. Our prescribing habits have evolved in the last 15 to 20 years. We have better discrimination of the woman most likely to benefit; improved therapy through use of newer formulations, dosages, routes, and schedules; and more appropriate implementation of monitoring procedures. Although questions remain, we should not let our imperfect knowledge dissuade us from more widespread prescribing of hormone replacement therapy.
Adrenergic hypersensitivity after beta-blocker withdrawal in hypertrophic cardiomyopathy. Withdrawal of beta-blocker therapy has been associated with the development of adrenergic hypersensitivity and adverse clinical effects in patients with coronary artery disease and hypertension. The aim of this study was to establish the occurrence and clinical significance of adrenergic hypersensitivity after abrupt withdrawal of long-term beta blockade in hypertrophic cardiomyopathy. Beta-adrenergic sensitivity was measured using the isoprenaline chronotropic dose25. Symptom assessment chronotropic dose25 calculation, bicycle exercise, echocardiography and Holter monitoring were performed while the patient received beta-blocker therapy and repeated on days 2, 4, 6, 8 (acute withdrawal period) and on day 21 after abrupt withdrawal. The study was terminated after 7 patients had been studied because all patients experienced a marked deterioration in symptoms and several clinical events had occurred. The chronotropic dose25 (mean +/- standard deviation) demonstrated beta 1-adrenergic hypersensitivity with a minimal value of 1.6 +/- 0.8 micrograms during the acute withdrawal period compared with 3.8 +/- 1.7 micrograms on day 21 (p = 0.003). Heart rates during rest and exercise showed an overshoot increase during the acute withdrawal period. The maximal 24-hour ventricular ectopic count was higher during the acute withdrawal period than during day 21 (p = 0.04). Of 3 patients with inducible outflow tract gradients, 2 developed resting gradients greater than 30 mm Hg during the acute withdrawal period. There was an increase in peak late filling velocity of mitral inflow after beta-blocker withdrawal. In conclusion, transient beta-adrenergic hypersensitivity occurs after beta-blocker withdrawal in hypertrophic cardiomyopathy and is associated with significant physiologic changes and adverse clinical consequences.
Pediatric fine-needle aspiration biopsy. A total of 135 fine-needle aspiration (FNA) biopsies from varying sites were performed in 123 children (mean, 10.5 years; range, one day to 18 years) over a five-year period. One hundred thirty (96.3%) biopsy specimens were satisfactory for evaluation. Seventy-nine cases were nonneoplastic (60.8%); among these cases, a specific diagnosis of infectious disease was made in 17 (13.1%). A diagnosis of neoplastic disease was made in 50 (38.5%) cases, of which 14 (10.8%) were benign, 28 (21.5%) were malignant, and 8 (6.2%) were neoplasms of uncertain biologic potential. The sensitivity of pediatric FNA biopsies was 90.6%, specificity 100%, positive predictive value 100%, negative predictive value 94.7%, and efficiency of the test 96.5%. There were no false-positive diagnoses and there were four false-negative diagnoses, three of which involved aspirates of the central nervous system (CNS). Ancillary studies, including immunocytochemistry (20 cases), electron microscopic examination (18 cases), microbiologic culture (8 cases), cytogenetic studies (7 cases), and flow cytometry (3 cases), were performed on the aspirated material, enabling a more specific diagnosis or supplying additional information in many cases. Definitive diagnosis by FNA biopsy enabled radiation therapy and/or chemotherapy to be administered for unresectable malignant neoplasms, provided material for culture of infectious lesions, identified benign lesions not needing surgery, and aided the surgeon in planning the extent of surgery in resectable malignant neoplasms. These results support the greater use of FNA biopsy in the pediatric population.
Effects of interferon on intrahepatic human leukocyte antigens and lymphocyte subsets in patients with chronic hepatitis B and C. We investigated the effects of interferon therapy on hepatocyte human leukocyte antigen class I and class II antigen expression and intrahepatic lymphocyte subsets in patients with chronic viral hepatitis B (n = 11) and C (n = 10). Interferon-alpha was administered intramuscularly in doses ranging from 3 to 18 million international units daily for 4 wk. Liver biopsy specimens were obtained just before and immediately after treatment, and the specimens were stained by the indirect immunoperoxidase method for evaluation of human leukocyte antigen expression and lymphocyte subsets. Before therapy, no significant difference was noted between hepatitis B and C in human leukocyte antigen class I antigen expression on hepatocytes or in the lymphocyte subsets in the intralobular and portal areas. After interferon-alpha treatment, hepatocyte expression of human leukocyte antigen class I antigens and serum beta 2-microglobulin levels were virtually unchanged in chronic viral hepatitis C patients, but both were increased in chronic viral hepatitis B patients. Human leukocyte antigen class II antigens were not expressed during treatment. The mean number of intralobular CD3+ and CD8+ cells and the mean serum ALT level decreased significantly in chronic viral hepatitis C patients (p less than 0.05) but not in chronic viral hepatitis B patients. The mean number of intralobular CD4+ cells was unaffected by interferon therapy in both groups. In all 21 patients, the changes in CD8+ cell numbers paralleled the changes in serum ALT levels. Our findings suggest that T-cell cytotoxicity may play an important role in hepatocyte damage in both chronic viral hepatitis C and chronic viral hepatitis B and that the response to interferon-alpha differs in these two types of hepatitis.