shukoor65/lab-rag-model huggingface dataset:
Delayed decline in plasma atrial natriuretic peptide levels after an abrupt reduction in atrial pressures: observation in patients with dual-chamber pacing. The effect of an abrupt reduction in atrial pressures on atrial natriuretic peptide (ANP) secretion was studied in four patients with complete atrioventricular block with a dual-chamber pacemaker when the pacing mode was changed from the VVI to the DVI mode at an equal rate of 70/min. Simultaneous continuous hemodynamic monitoring was performed using a balloon-tipped thermodilution catheter. With DVI pacing, there was an immediate decrease of right atrial pressure from 4.5 +/- 0.9 to 1.8 +/- 1.1 mm Hg, and a reduction of pulmonary arterial wedge pressure from 7 +/- 0.8 to 4.5 +/- 0.9 mm Hg, together with a rise in cardiac output from 3.1 +/- 0.2 to 3.7 +/- 0.2 L/min. However, despite a constant hemodynamic status after dual-chamber pacing, the arterial ANP level steadily decreased from 151 +/- 26 pg/ml to a steady low level of 78 +/- 15 pg/ml after 20 minutes of dual-chamber pacing (percentage reduction- 48 +/- 8%, p less than 0.05). This persisted until the end of the study at 60 minutes. The time-dependent decay in ANP secretion after an abrupt and constant change in hemodynamic status should be considered when interpreting ANP levels.
Comparison of the effects of streptokinase and tissue plasminogen activator on regional wall motion after first myocardial infarction: analysis by the centerline method with correction for area at risk. In a trial of streptokinase versus recombinant tissue-type plasminogen activator (rt-PA) for a first myocardial infarction, 270 patients were randomized. Regional left ventricular function was assessed in 214 patients at 3 weeks. The infarct-related artery was the left anterior descending artery in 78 patients, the right coronary artery in 122 and a dominant left circumflex artery in 14. Analysis was by the centerline method with a novel correction for the area of myocardium at risk, whereby the search region was determined by the anatomic distribution of the infarct-related artery. Infarct-artery patency at 3 weeks was 73% in the streptokinase group and 71% in the rt-PA group. Global left ventricular function did not differ between the two groups. Mean chord motion (+/- SD) in the most hypokinetic half of the defined search region was similar in the streptokinase and rt-PA groups (-2.4 +/- 1.5 versus -2.3 +/- 1.3, p = 0.63). There were no differences in hyperkinesia of the noninfarct zone. Compared with conventional centerline analysis, regional wall motion in the defined area at risk was significantly more abnormal. The two methods correlated strongly, however (r = 0.99, p less than 0.0001), and both methods produced similar overall results. Patients with a patent infarct-related artery and those with an occluded artery at the time of catheterization had similar levels of global function (ejection fraction 58 +/- 12% versus 57 +/- 12%, p = 0.58).
Expression of neural cell adhesion molecule (NCAM) isoforms in neuroblastoma. A comparative study on the expression of the neural cell adhesion molecule (NCAM) in human neuroblastoma cell lines and tissues was undertaken. NCAMs are a family of closely related cell surface glycoproteins involved in cell-cell interactions. Using antibodies that recognise distinct epitopes on NCAM, their presence was shown in neuroblastoma, but these studies do not yield any information on the specific NCAM isoforms associated with the tumour. Western and Northern blot analyses were therefore carried out to characterise the NCAM isoforms in this neuroectodermal tumour. Western blot studies using the monoclonal antibody ERIC-1 showed that all human neuroblastoma cell lines tested expressed the 140 and 120 kilodalton isoforms of NCAM in their desialo state. Some of the cell lines also expressed NCAM-180. The data are corroborated by Northern blotting where a transcript of 7.4 kilobase pairs was identified only in lines expressing NCAM-180; the 6.7 and 5.4 kilobase pair transcripts coding for 140 and 120 kilodalton isoforms, respectively, were present in all the cell lines tested. The NCAM isoforms identified in neuroblastoma were also different from those found in adult and fetal brain tissue, suggesting that aberrations are expressed in the molecule during tumorigenesis.
Quantitative nailfold capillary microscopy in cutaneous and systemic lupus erythematosus and localized and systemic scleroderma. Quantitative television microscopy of nailfold capillaries of the fingers was performed in 12 patients with cutaneous lupus erythematosus (six with discoid type and six with disseminated type), in six patients with localized scleroderma (two with circumscribed type, two with linear types, and two with atrophic type), in 10 patients with systemic lupus erythematosus, and in eight patients with systemic scleroderma. The following features were analyzed and compared with a control group (n = 15) of similar age: venous plexus visibility; density of capillaries; avascular fields; hemorrhages; giant capillaries; diameters of the transitional segment, the arterial, and the venous limbs; loop width; and flow stop caused by local cooling test. The patient groups with cutaneous lesions only showed no essential differences as compared with the controls. Patients with systemic scleroderma differed in almost every finding from the controls and from patients with localized scleroderma. Patients with systemic lupus erythematosus exhibited significant differences in several findings as compared with the controls and the cutaneous lupus erythematosus group, but there was overlap.
The new 99mTc myocardial perfusion imaging agents: 99mTc-sestamibi and 99mTc-teboroxime. The two new 99m (99mTc) labeled myocardial perfusion agents, 99mTc-Sestamibi and 99mTc-Teboroxime, are now available for routine clinical application. Both agents allow assessment of ejection fraction by the first-pass technique at rest or during exercise, thus providing additional information not available with thallium-201. 99mTc-Sestamibi has long myocardial residence time, as well as adequate myocardial extraction, providing images of higher count density and superior quality compared with thallium-201. 99mTc-Teboroxime has excellent myocardial uptake characteristics but is cleared very rapidly from the myocardium. Both tracers have shown results similar to those obtained with thallium-201 for detection of coronary artery disease and the assessment of defect reversibility. 99mTc-Sestamibi studies using the rest/stress imaging sequence can be accomplished in approximately 5 hours; studies using dual-isotope imaging (rest thallium-201 and stress 99mTc-Sestamibi injection) can be completed in 1 to 2 hours. Gated stress images can be performed with 99mTc-Sestamibi, providing simultaneous information of myocardial perfusion at stress and resting wall motion or thickening and allowing rapid differentiation of ischemic from infarcted tissue. Because of its slow myocardial clearance and absence of redistribution, 99mTc-Sestamibi allows uncoupling of the time of injection from the time of imaging and thus can be valuable in the evaluation of acute myocardial infarction and outcome of thrombolytic therapy. With 99mTc-Teboroxime, rapid serial studies are feasible. Pharmacologic stress and rest studies with 99mTc-Teboroxime single photon emission computed tomography potentially can be completed in under 30 minutes.
Spontaneous carotid-cavernous fistulae in Ehlers-Danlos syndrome Type IV. Case report. Spontaneous bilateral carotid-cavernous fistulae and cervical artery dissection is reported in a 20-year-old woman with Ehlers-Danlos syndrome Type IV. The clinical features of 16 previously published cases of spontaneous carotid-cavernous fistulae associated with Ehlers-Danlos syndrome Type IV are reviewed, for a total of 17 cases. The mean age of the 14 women and three men was 31.6 years. Only direct fistulae were encountered. Diagnostic neuroangiography carried morbidity and mortality rates of 36% and 12%, respectively; neuroradiological treatment resulted in death in one of six patients. The possible value of desmopressin in the management of these patients is discussed. In view of the risks of arterial puncture and surgery, the authors emphasize the importance of early recognition of Ehlers-Danlos syndrome.
PUVA and cancer: a large-scale epidemiological study. There is concern about the long-term carcinogenic effects of psoralen and ultraviolet A radiation (PUVA) therapy for treatment of skin disorders. A study of 4799 Swedish patients (2343 males, 2056 females; mean age at first treatment 45.3 years, range 6-93; mean follow-up 6.9 years males, 7.2 years females) who received PUVA between 1974 and 1985 showed a dose-dependent increase in the risk of squamous cell cancer of the skin. Male patients who had received more than 200 treatments had over 30 times the incidence of squamous cell cancer found in the general population. Significant increases (p less than 0.05) were also found in the incidences of respiratory cancer in males and females, pancreatic cancer in males, and kidney and colonic cancer in females. This study confirms previous reports of a dose-dependent increase in the incidence of squamous cell cancer in patients treated with PUVA.
Protection provided by hepatitis B vaccine in a Yupik Eskimo population. Seven-year results. The long-term immunogenicity and protection provided by a plasma-derived hepatitis B vaccine (Heptavax B) was determined in a cohort of susceptible persons immunized in 1981. In this study 1581 susceptible persons were immunized with the recommended three-dose regimen of hepatitis B vaccine. After 7 years, 74% of vaccinees retained antibody to hepatitis B surface antigen (anti-HBs) levels of 10 mIU/mL or more. Anti-HBs levels at 7 years varied inversely with age and directly with the level of anti-HBs attained 1 year after the first dose. During the 7 years after the first dose of vaccine, five vaccine responders and three other persons developed antibody to hepatitis B core antigen and their level of anti-HBs increased. None developed detectable hepatitis B surface antigen or clinical hepatitis. This update of an ongoing study continues to suggest that the risk of hepatitis B virus infection to most persons with an initial anti-HBs response to hepatitis B virus vaccine of 10 mIU/mL or greater is low, regardless of the initial antibody level.
Surgical implications of drug-induced rhabdomyolysis. Four cases are described of acute non-traumatic rhabdomyolysis with subsequent development of a compartmental syndrome, requiring extensive fasciotomies. All the patients were young male alcoholics who were taking benzodiazepines as part of an addiction treatment programme. In this risk group clinicians should be aware of two serious complications of non-traumatic rhabdomyolysis: acute renal failure and compartmental syndrome.
Prolonged hypofibrinogenemia and protein C activation after envenoming by Echis carinatus sochureki. Following envenomization by Echis carinatus sochureki, a professional snake handler developed a profound coagulopathy manifested by hemorrhage from the bite site, venipuncture sites and gums; coagulation testing revealed prothrombin and partial thromboplastin times greater than 150 seconds, a fibrinogen of 0 mg%, and marked elevation of fibrin degradation products. In addition, protein C antigen levels were undetectable. The coagulopathy was treated with cryoprecipitate; two different antivenoms were also administered with uncertain benefit. Subsequently, the properties of the venom and antivenoms were studied. Venom did not directly clot fibrinogen; however, venom concentrations as low as 0.2 micrograms/ml caused significant prothrombin activation. In addition, venom activated protein C in the absence of thrombomodulin, and this activity was inhibited by hirudin. The ability of four commercial antivenoms to neutralize the venom prothrombinase and hemorrhagic activity was measured. Three of the four antivenoms partially neutralized venom-induced prothrombin activation. Extreme differences in efficacy were found among the four antivenoms in neutralizing venom hemorrhagic activity in mice. This case illustrates the difficulty in managing the complex coagulopathy that can result from exotic snake envenomization, and identifies a new coagulant property of Echis carinatus venom (protein C activation).
Abnormal diastolic left ventricular filling by pulsed Doppler echocardiography in patients on continuous ambulatory peritoneal dialysis. To determine characteristics of diastolic left ventricular (LV) function in patients on continuous ambulatory peritoneal dialysis (CAPD), two groups of CAPD patients without (n = 23; group 1) vs with (n = 25; group 2) LV hypertrophy (greater than 13 mm) were compared with a group of untreated non-renal hypertensive patients with LV hypertrophy (n = 11; group 3) using Doppler-echocardiography. Age and body surface area were comparable in all three groups, mean CAPD-duration (32 +/- 28 vs 26 +/- 23 months; p = NS) was comparable in renal patients. LV systolic function in echocardiography (LVEF: 62 vs 64 vs 63%) and systolic time intervals were normal and comparable in all three groups. Atrial maximum filling velocities (96 +/- 25 vs 91 +/- 25 vs 67 +/- 8 cm/s) were comparably increased, the ratio of maximal early/atrial filling velocities was comparably decreased (0.73 +/- 0.25 vs 0.77 +/- 0.21 vs 0.99 +/- 0.05) in both groups of renal patients as compared to group 3 (p less than 0.05-0.01). Atrial filling fractions were increased in all three groups, more pronounced in group 1 than in group 3 (50 +/- 11 vs 40 +/- 7%; p less than 0.05). The normal correlation of Doppler parameters with age and with LV radius/thickness ratio was altered in renal patients such that high patient age tended to have an additional negative influence on LV diastolic function of hypertrophied, but not of normal myocardium. Isovolumic relaxation time was prolonged in all three groups (134 +/- 38 vs 131 +/- 34 vs 116 +/- 17 ms; p = NS). We conclude that in patients on CAPD, diastolic LV filling is impaired both in normal and hypertrophied myocardium. High age is a factor that further attributes to diastolic dysfunction of hypertrophied myocardium in CAPD.
A randomized study of on-line plasma perfusion over protein A-sepharose and 5-fluorouracil chemotherapy in patients with metastatic colorectal carcinoma. To evaluate the safety of on-line plasma perfusion over protein-A sepharose and the therapeutic advantage of combining plasma perfusion (PP) over protein-A sepharose with 5-fluorouracil (5-FU) chemotherapy in patients with metastatic colorectal carcinoma (MCRC), thirty patients were randomized after surgery of primary CRC to receive a combination of 5-FU and PP over protein-A sepharose (group A), or a combination of 5-FU and PP over sepharose (group B), or 5-FU alone (group C). Bi-weekly on-line PP over 200 ml protein-A sepharose gel (group A) or 200 ml sepharose gel (group B) were performed with a Cobe 2997 blood cell separator for a maximum of 19 treatments per patient. 5-FU was given at 1000 mg/m2/d on days 1-5 of a 4-weekly cycle until progression. PP was well tolerated and no severe or life-threatening toxicity was observed. Mild clinical side-effects consisted of fever and chills (36% in group A, 23% in group B). The most common biological effects of PP over protein-A sepharose were significant drops in IgG (66% of pre-PP values), CH50 and C3 (73% of pre-PP values) and a significant generation of C3a and C5a anaphylatoxins. Tumor response rates were 40% for group A, 0% for group B and 20% for group C. The median survival times tended to be longer in group A (17 months) than in group B (10 months) and in group C (9 months). This is the first randomized trial showing some therapeutic advantage in combining PP over protein-A sepharose with conventional chemotherapy in MCRC.
Preoperative hemostatic assessment of the adenotonsillectomy patient. Intraoperative or postoperative hemorrhage in the patient who has undergone an adenotonsillectomy because of an unrecognized hemostatic defect may increase morbidity and can be potentially life-threatening to the patient in what should be a "routine" procedure. Preoperative identification of occult hemostatic abnormalities, coupled with perioperative management directed at correcting the effects of the defects, should serve to reduce the incidence of this distressful complication. Routine use of preoperative laboratory screening tests for this purpose has been discouraged recently as a result of concerns over cost-effectiveness and the low predictiveness of the tests for bleeding. Our experience with the routine use of a comprehensive hemostatic laboratory screening panel--which includes a bleeding time test--in the adenotonsillectomy patient population demonstrated that 11.5% of our patients had abnormal initial screening laboratory tests; these results were ultimately attributable to occult hemostatic defects. Clinical history, the universally recommended method of preoperative hemostatic assessment, failed to detect any previously unrecognized coagulation disorder. Laboratory screening improved preoperative detection of occult hemostatic defects and allowed for appropriate alterations in perioperative care. Our results with this approach are presented, along with illustrative case histories and a discussion of the current recommendations for preoperative laboratory screening of the hemostatic system, as found in a review of the literature.
Comparison of celiprolol and propranolol in stable angina pectoris. Celiprolol International Angina Study Group. The comparative antianginal effects and safety of propranolol and celiprolol, a highly beta 1-selective adrenoceptor blocker with selective partial beta 2-adrenoceptor agonist activity, were assessed in an international multicenter, placebo run-in, active control, double-blind, randomized, titration-to-effect study of 140 patients with stable, exercise-induced angina pectoris. At baseline, all patients received placebo for 2 weeks, then titrated doses of once-daily celiprolol (200, 400, 600 mg) or twice-daily propranolol (total daily dose 80, 160, 320 mg) over 4 weeks, followed by a 2-week maintenance period. Heart rate and blood pressure, at rest and with exercise, weekly anginal attack frequency, nitroglycerin consumption and symptom-limited treadmill exercise times (modified Bruce protocol) were assessed. Compared with their respective baselines, both celiprolol and propranolol reduced anginal attack and nitroglycerin consumption rates to a comparable degree, while improving exercise tolerance (p less than 0.05). Treatment with propranolol compared with celiprolol, however, was associated with a significantly lower heart rate at rest (p less than 0.01). The double-product at the conclusion of exercise testing was significantly reduced by both drugs. Celiprolol and propranolol had similar effects on blood pressure, and were well tolerated. More symptomatic bradycardia occurred with propranolol. Despite the differences in their hemodynamic actions, once-daily celiprolol is as effective as twice-daily propranolol in the treatment of patients with stable angina pectoris.
Exclusion of cervical spine injury: a prospective study. Trauma room lateral cervical spine radiographs (LCSR) may improve the safety of intubation and transportation of multiply injured patients by providing earlier recognition of spinal vertebral injuries. We prospectively evaluated 60 consecutive trauma admissions to determine the impact of clearance of cervical spine radiographs on patient care. Fifty-three patients had no cervical spine injury (CSI). Intubations, emergency head CT scan, aortography, or urgent operation (less than 6 hours after admission) were required in the majority of patients and preceded complete cervical spine clearance in all but one instance. The median time for radiologic clearance of the cervical spine was 15 hours (range, 1.5 to 181). LCSR failed to identify three of the seven acute CSI (all three had C7 fractures). The spine-injured were managed with cervical collars and no new neurologic injury developed. We conclude that: 1) LCSRs do not appear to alter urgent management of multiply injured patients during resuscitation and transportation; 2) chest radiographs and emergency investigations should not be delayed by repeated LCSR in the trauma room as it may be difficult to fully exclude CSI in many trauma patients; 3) we support the current ATLS guidelines, which suggest that all patients should be presumed to have an unstable CSI until the presence of cervical injury has been excluded.
Access to health care in the United States: barriers for neurologic patients, challenges for neurologic physicians Approximately 34 million people in the United States have no health insurance. Up to 80 million people have insurance inadequate to provide care for severe or long-term illness (the underinsured). In 1986, an estimated 1 million persons in the US could not obtain needed health care for financial reasons, and another 18.8 million had difficulty obtaining care. There probably are 3.2 million people with neurologic disorders among the 34 million uninsured, and more among the underinsured. Those patients probably have difficulty obtaining health care, including neurologic consultations, laboratory tests, and radiologic procedures. Congress and many state legislatures are considering various proposals to address the problems of the un- and underinsured. Several national medical professional societies have developed programs to improve access to care for their patients. The American Academy of Neurology Task Force on Access to Health Care is studying access to care for neurologic patients and will recommend a course of action to the Academy. The Task Force welcomes suggestions concerning appropriate steps to improve access to health care for patients with neurologic disorders.
Incidence and timing of hypothermia in trauma patients undergoing operations. Hypothermia is a major problem in patients who have sustained trauma. We reviewed the cases of 100 consecutive trauma patients transferred directly to the operating room (OR) from the Emergency Department (ED) in a Level I trauma center; 26 cases could not be evaluated. Forty-two patients (57%) became hypothermic at some time between injury and leaving the OR. Fifty-five patients (74%) had a temperature (T) recorded on arrival to the ED; but only 7 (12%) were hypothermic (34.7 degrees +/- 1.5 degrees C). In contrast, 34 patients (46%) arrived in the OR hypothermic (34.8 degrees +/- 0.9 degrees C) and 26 (76%) of these left the OR hypothermic (34.8 degrees +/- 0.9 degrees C). Eight additional patients (20%) arriving in the OR with a T greater than 35.9 degrees C left the OR hypothermic (35.1 degrees +/- 0.4 degrees C). The mean T loss in the ED was significantly greater than that lost in the OR (-0.8 degrees +/- 0.7 degrees C vs. 0.0 degrees +/- 0.6 degrees C; p less than 0.0001, ANOVA). Ninety-two percent of the patients lost temperature in the ED, while 43% of the patients gained temperature in the OR. Hypothermia was associated with lower Trauma Scores, and those patients who were severely hypothermic received more intravenous fluids. However, the impact of fluid infusion was not independent from Trauma Score and did not fully explain the magnitude of the heat loss. These data suggest that hypothermia in trauma patients has a multifactoral etiology related to the magnitude of injury and that the major T loss occurs in the ED rather than in the OR.