shukoor65/lab-rag-model huggingface dataset:
Injury current and gradients of diastolic stimulation threshold, TQ potential, and extracellular potassium concentration during acute regional ischemia in the isolated perfused pig heart. During acute regional myocardial ischemia, a "current of injury" flows between the ischemic and the normal tissue. Its direction and magnitude change during the cardiac cycle. During diastole, the injury current flows intracellularly from the ischemic cells toward the normal cells and tends to depolarize the latter. The gain insight into the possible role of the injury current in arrhythmogenesis, we simultaneously determined diastolic stimulation threshold, [K+]o and TQ potential at multiple sites closely spaced across the cyanotic border in Langendorff-perfused pig hearts during the first 10 minutes after occlusion of the left anterior descending coronary artery. The position of the electrodes relative to the border was validated by their response to 1) regional ischemia and 2) selective perfusion with a high-K+ perfusate of the left anterior descending coronary artery. A temporary decrease of diastolic stimulation threshold preceded a rapid increase in the central ischemic zone; a lasting reduction (by +/- 20%) without a concomitant increase of [K+]o was observed at seven sites (of 39 sites tested), five of which were less than 2 mm outside the electrophysiological border. Moreover, up to 4 mm inside the electrophysiological border, a similar lasting decrease of diastolic stimulation threshold was accompanied by a moderate increase of [K+]o. We conclude that 1) the injury current causes increased excitability in normal tissue close to the "ischemic" border and 2) increased excitability related to a moderately increased [K+]o may persist up to 10 minutes of ischemia at the ischemic side of the border. Both factors may facilitate the induction of life-threatening arrhythmias in acute myocardial ischemia.
Intraoperative facial nerve monitoring: prognostic aspects during acoustic tumor removal. Intraoperative facial nerve monitoring with electrical stimulation (IFNMES) has become an integral part of acoustic tumor surgery. We reviewed the records of fifty-six patients who underwent translabyrinthine acoustic tumor removal with IFNMES. There was excellent correlation between intraoperative facial nerve activity and immediate postoperative facial nerve function (24 hours after surgery and at hospital discharge). Our data would suggest that patients who exhibit less than 500 microvolts of ongoing EMG activity during surgery, and who yield at least a 500-microvolt contraction when stimulated with 0.05 milliamps at the brainstem after tumor removal, can expect an excellent immediate facial nerve result (grade I or II).
Diskitis in children. Thirty-six patients diagnosed with diskitis from 1978 to 1988 and followed for an average of 29.2 months were reviewed. The study included 23 boys and 13 girls with an average age of 5.3 years. The initial symptoms varied, but distinct clinical patterns emerged and were identifiable in different age groups. Both the leukocyte count and sedimentation rate were elevated. Routine roentgenograms were positive for intervertebral disk space narrowing in 82% of cases, technetium bone scans positive in 72%, and magnetic resonance imaging positive in all recent cases. Treatment consisted of bed rest for all patients, plaster casts for 50%, antibiotics for 40%, and traction for 23%. Regardless of the treatment combination, the course of the disease in most children is benign. At the completion of the study, all patients were asymptomatic including three children who had recurrences. In spite of being asymptomatic, 74% had persistent roentgenographic changes. The administration of antibiotics appears to be appropriate when indicated, i.e., failure to respond to immobilization. Disk space aspiration or biopsy should be reserved for those cases that are refractory to immobilization and antibiotics.
The autotransfusion effect of external leg counterpressure in simulated mild hypovolemia. We examined the cardiovascular response of external leg counterpressure in healthy volunteers at 100 mm Hg compression pressure. To stimulate mild hypovolemia, measurements were made with the subjects in a 60 degrees head-up tilt position. Left ventricular end-diastolic volume (LVEDV) and cardiac output (CO) were calculated from two-dimensional echocardiography. Flow through the inferior vena cava (IVC) below the origin of the hepatic veins was determined by the Doppler ultrasound technique. The application of counterpressure significantly increased LVEDV, CO, and arterial blood pressure over that seen with tilting without the device. These responses were accompanied by a small but significant increase in IVC flow. We therefore concluded that external leg counterpressure transferred blood to the central circulation by compression of the venous capacitance vessels (an autotransfusion effect) in mild hypovolemia, but such an effect may not benefit patients in a hypovolemic shock state because of the small amount of translocated blood.
Cardiovascular reflexes and autonomic dysfunction in Parkinson's disease. Cardiovascular reflexes were analysed in a group of 20 patients suffering from Parkinson's disease and in 12 age-matched healthy subjects, in order to ascertain the incidence and degree of autonomic dysfunction. The following were measured: heart rate variation during normal breathing, postural change (30/15 ratio) and during the Valsalva manoeuvre: blood pressure variation after standing. These measurements were taken at least 12 h after therapy had been withdrawn and were repeated after therapy had been resumed. Significant changes in the different heart rate variation indices were found in the parkinsonian patients which correlated with the duration and severity of the extrapyramidal symptomatology. After standing the patients showed a significant drop in blood pressure, when compared respectively with their base values and with the response in controls. Anticholinergic drugs had no significant effect on the heart rate variation indices, whereas antiparkinsonian therapy seems to have contributed to the drop in blood pressure after standing.
Dysfibrinogenemia associated with thrombosis and third-trimester fetal loss. A case report. Dysfibrinogenemias are rare genetic disorders that are clinically silent, cause a mild bleeding tendency or have thromboembolic manifestations. During pregnancy they often cause hemorrhage and first-trimester abortions. A patient with a severe thrombotic tendency during pregnancy had a third-trimester fetal loss.
Comparative effects of APSAC and rt-PA on infarct size and left ventricular function in acute myocardial infarction. A multicenter randomized study. BACKGROUND. Recombinant tissue-type plasminogen activator (rt-PA or alteplase) and anisoylated plasminogen streptokinase activator complex (APSAC or anistreplase) have been demonstrated to limit infarct size significantly and to preserve left ventricular function when injected soon after acute myocardial infarction. However, as yet, the efficacy and safety of these two thrombolytic agents have not been directly compared in one trial; this was the aim of this study. METHODS AND RESULTS. One hundred eighty-three patients suffering from a first acute myocardial infarction were randomly allocated to either APSAC (30 units over 5 minutes) or single-chain rt-PA (100 mg over a 3-hour period) within 4 hours of the onset of symptoms. Global and regional left ventricular function were assessed from contrast angiography an average of 5.3 +/- 2.3 days after initial therapy. Radionuclide angiography and thallium-201 single-photon emission computerized tomography were performed before hospital discharge. Infarct size was assessed by single-photon emission computerized tomography and expressed in percentage of the total myocardial volume. Ninety patients received APSAC and 93 received rt-PA within a mean period of 172 +/- 52 minutes after the onset of symptoms. The two groups were similar in age, location of the acute myocardial infarction, Killip class, and time of randomization. The patency rate of the infarct-related artery was 72% in the APSAC group and 76% in the rt-PA group (NS). Initial and predischarge left ventricular ejection fraction as well as infarct size were similar in both therapeutic groups (0.50 +/- 0.14 versus 0.52 +/- 0.12 for initial and 0.48 +/- 0.10 versus 0.47 +/- 0.10 for predischarge ejection fraction, 11 +/- 7% versus 9 +/- 7% for infarct size, respectively, for APSAC- and rt-PA-treated patients). Bleeding complications requiring blood transfusion occurred in one APSAC patient and in two rt-PA patients. One patient in the rt-PA group died of a massive intracranial hemorrhage. At the end of the 3-week follow-up period, five APSAC patients (5.5%) and seven rt-PA patients (7.5%) had died. CONCLUSIONS. The early infusion of APSAC or rt-PA in acute myocardial infarction produced a similar patency rate, limitation of infarct size, and preservation of left ventricular systolic function with an equivalent rate of bleeding complications.
Detection of field change in oral cancer using oral exfoliative cytologic study. Four smears were taken from the normal buccal mucosa of 55 oral cancer patients and 76 cancer-free patients. In each case, two were stained by the Papanicolaou method and two underwent Feulgen hydrolysis. Quantitative assessment of nuclear area (NA) and cytoplasmic area (CA) of the Papanicolaou smears was undertaken using a semiautomatic image analysis system. DNA profiles were assessed from the Feulgen smears using a Vickers M85 microdensitometer (Vickers Instruments, York, England) and were found to be diploid for all patients. Results were then analyzed with respect to those patients who took alcohol, tobacco, combination of alcohol and tobacco, and those who took neither. A significant reduction in CA for the oral cancer group (P equals 0.001) but no change in NA (P equals 0.74) was observed. A detailed analysis of alcohol and tobacco habits could identify no significant role for these two factors, in the reduction in cytoplasmic area. Such field change may prove to be of value in predicting the development of second malignant tumors.
Fever: knowledge, perception and attitudes. Results from a Norwegian population study. To investigate the layman's knowledge, perception and attitudes regarding normal body temperature, fever, infections and the effect of penicillin on virus infections a representative sample of the Norwegian population (619 women and 592 men over the age of 15) was interviewed in 1988 as part of a monthly national opinion poll. One-third thought body temperatures up to 40.5 degrees C to be life-threatening, but the results do not justify the application of the term 'fever phobia' as described in other studies based on non-representative samples. More respondents were afraid of viral infections (48%) than bacterial infections (9%), which may be due to the media focus upon the HIV/AIDS epidemic. Thirty-five per cent believed penicillin to be effective against virus infections. Educational programmes on fever should also include information about virus infections and their treatment.
Assessment of response to cancer therapy using fluorine-18-fluorodeoxyglucose and positron emission tomography. In order to evaluate the usefulness of 18F-FDG PET in the assessment of therapeutic effects, FDG-PET studies were performed both before and after therapy in 26 patients with miscellaneous malignant tumors. The change in FDG uptake by therapy was compared with the change in tumor size and prognosis. All 26 lesions had a high FDG uptake before therapy. Five of seven lesions which had a relatively low FDG uptake before therapy showed no change or increase in tumor size by therapy. The decreased FDG uptake after therapy was more prominent in the partial response group than in the no change group. FDG uptake before therapy in the non-relapse group was higher than that in the relapse group. However, a decreased FDG uptake did not necessarily indicate a good prognosis. One patient with no change in tumor size and a decreased FDG uptake had no recurrence. This suggests that FDG-PET has a complementary role in the assessment of therapeutic effects.
Differential effect of compression-ischaemia block on warm sensation and heat-induced pain. The effect of compression-ischaemia nerve block on psychophysical thresholds for warm sensation and heat-induced pain was studied on 19 normal human volunteers. Although those two sensory submodalities should be predicted to block simultaneously, based on the fact that both are served by unmyelinated primary afferents, it was actually found that warm sensation was much more vulnerable to compression-ischaemia than heat-induced pain. This is interpreted as resulting from different summation requirements for each of the two sensory modalities; sensation of warmth depends on spatial summation to a larger extent than heat-induced pain. Such differential vulnerability is in line with recent clinical studies reporting deterioration of warm sensation associated with preservation of heat pain in peripheral nerve disorders caused by diabetes, ageing and other neuropathic processes.
Acoustic schwannomas in children. The clinical presentation and treatment of three cases of acoustic schwannoma occurring in children are described. All the tumors were detected late, when they had attained a large size and were extremely vascular. The use of preoperative tumor embolization as an adjunct to surgical excision is discussed.
Hepatofugal arterial signal in the main portal vein: an indicator of intravascular tumor spread. Five patients with thrombosis of the main portal vein underwent Doppler ultrasound (US). Three of these patients had confirmed hepatocellular carcinoma. Doppler US allowed differentiation between bland thrombus and tumor thrombus in two of the three patients. Tumor thrombus of the main portal vein was characterized at US by an intraportal arterial waveform in a hepatofugal direction.
Differentiation of hydrocephalic calf and human calvariae. Occasionally, partial calvariae of hydrocephalic calves are found in forensic contexts and mistakenly identified as human. Such specimens can be properly identified through immunological assessment of associated soft tissue, microscopic analysis of associated hair, and morphological comparison with documented museum specimens. Morphological comparison should focus on the form of the occiput, supraorbital grooves, and bulbous vault and presence of coronal processes.
Risk factors for infusion-related phlebitis with small peripheral venous catheters. A randomized controlled trial. OBJECTIVE: To identify risk factors for infusion-related phlebitis with peripheral intravenous catheters. DESIGN: A randomized trial of two catheter materials, with consideration of 21 potential risk factors. SETTING: A university hospital. PATIENTS: Hospitalized adults without granulocytopenia who received a peripheral intravenous catheter. INTERVENTIONS: House officers or ward nurses inserted the catheters, and each insertion was randomized to a catheter made of tetrafluoroethylene-hexafluoropropylene (FEP-Teflon) or a novel polyetherurethane without leachable additives (PEU-Vialon). MEASUREMENTS: Research nurses scored insertion sites each day for inflammation and cultured catheters at removal. RESULTS: The Kaplan-Meier risk for phlebitis exceeded 50% by day 4 after catheterization. intravenous antibiotics (relative risk, 2.00), female sex (relative risk, 1.88), prolonged (greater than 48 hours) catheterization (relative risk, 1.79), and catheter material (PEU-Vialon: FEP-Teflon) (relative risk, 0.73) strongly predicted phlebitis in a Cox proportional hazards model (each, P less than 0.003). The best-fit model for severe phlebitis identified the same predictors plus catheter-related infection (relative risk, 6.19), phlebitis with a previous catheter (relative risk, 1.54), and anatomic site (hand: forearm, relative risk, 0.71; wrist:forearm, relative risk, 0.60). The low incidence of local catheter-related infection was comparable with the two catheter materials (5.4% [95% CI, 3.8% to 7.6%] and 6.9% [CI, 4.9% to 9.6%]); none of the 1054 catheters prospectively studied caused bacteremia. CONCLUSIONS: Multiple factors, including the infusate and the duration of cannulation, contribute to the development of infusion-related phlebitis. The use of peripheral intravenous catheters made of PEU-Vialon appears to pose the same risk for catheter-related infection as the use of catheters made of FEP-Teflon, and PEU-Vialon can permit longer cannulation with less risk for phlebitis. The risk for catheter-related bacteremia with FEP-Teflon and PEU-Vialon catheters is sufficiently low that it no longer seems justifiable to recommend the use of small steel needles for most peripheral intravenous therapy.
Surgical depilation for the treatment of pseudofolliculitis or local hirsutism of the face: experience in the first 40 patients. Forty patients underwent surgical depilation for pseudofolliculitis barbae or local hirsutism of the face during a 15-year period. The operative method and its results and pitfalls are discussed. Although it is not the treatment of choice, this operation is very useful when other therapy has not been successful. This seems especially true in male-to-female transsexuals.
Muscle structure and performance capacity of Himalayan Sherpas. The ultrastructure of the vastus lateralis muscle of Sherpas from Nepal [5 males; age 28 +/- 2.8 (SD) yr, indirect maximal O2 consumption 48.5 +/- 5.4 ml.kg(-1).min(-1)] was assessed and compared with those of sedentary lowlanders and of Caucasian climbers before and after high-altitude exposure. The mean cross-sectional area of the fibers was 3,186 +/- 521 microns2, i.e., similar to those of Caucasian elite high-altitude climbers (3,108 +/- 303 microns2) and a group of climbers after a 6- to 8-wk sojourn at 5,000-8,600 m (3,360 +/- 580 microns2) but significantly (P less than 0.05) smaller than that of unacclimatized climbers (4,170 +/- 710 microns2) and slightly, although not significantly, lower than that of sedentary lowlanders (3,640 +/- 260 microns2). The number of capillaries per square millimeter of muscle cross section was 467 +/- 22, not significantly smaller than those of climbers on return from a Himalayan expedition (538 +/- 89) and elite high-altitude climbers (542 +/- 127) but significantly (P less than 0.05) greater than that of sedentary lowlanders (387 +/- 25). The volume density of mitochondria was 3.96 +/- 0.54%, significantly (P less than 0.05) less than the values found for any other investigated group, including sedentary subjects at sea level (4.74 +/- 0.30%). It is concluded that Sherpas, like acclimatized Caucasian climbers, are characterized by 1) facilitated convective and diffusive muscle O2 flow conditions and 2) a higher maximal O2 consumption-to-mitochondrial volume ratio than lowlanders despite a reduced mitochondrial volume density.
Test-retest reliability of isokinetic knee extension and flexion torque measurements in persons with spastic hemiparesis. The purpose of this study was to evaluate and compare the test-retest reliability of isokinetic torque measurements in the involved and uninvolved knee musculature of 20 subjects with spastic hemiparesis. An isokinetic dynamometer was used to measure maximal voluntary knee extension and flexion at 60 degrees and 120 degrees/s. Peak torque (PT) and average peak torque (APT) data were collected from five repetitions on two separate occasions. Average peak torque was defined as the mean of the PT values obtained during each of the five repetitions. Spasticity was measured in the involved knee musculature prior to isokinetic testing using the Ashworth Scale. Pearson Product-Moment Correlation Coefficients and intraclass correlation coefficients (ICCs) were high (greater than or equal to .90) for both knees for PT and APT at both angular velocities. No clinically meaningful differences were found between the Pearson correlation coefficients and the ICCs of the involved versus the uninvolved knee for any testing conditions. We concluded that isokinetic evaluation of torque, as measured by PT and APT in subjects with spastic hemiparesis, can yield reliable results in both extremities.
Thrombogenic microballoon for cerebral aneurysms, arteriovenous malformations, and carotid cavernous fistula occlusion. Preliminary technical note. A thrombogenic microballoon was developed to overcome the problems of cerebral aneurysm rupture during microballoon inflation and incomplete aneurysm obliteration by microballoons with subsequent fatal rupture. These complications occur in about 35% of reported series with current microballoon embolization techniques. The wall of the new thrombogenic microballoon allows 80% aneurysm occlusion by inflation, thus avoiding mechanical rupture, and at the same time it produces a blood clot in the space remaining between the microballoon and the aneurysm wall. This clot undergoes fibrosis with firm adherence of the microballoon to the aneurysm wall. Experimental evidence is presented to support these conclusions. This thrombogenic microballoon system is also applicable to carotid-cavernous fistulas and arteriovenous malformations.
Resternotomy in patients with valved conduits adherent to the sternum. Twenty-two patients with valved conduits adherent to the sternum underwent resternotomy. Mean age was 10 +/- 6 years, and mean conduit age was 4 +/- 4 years. Diagnoses were D-transposition (7), truncus arteriosus (7), univentricular heart (6), Taussig-Bing anomaly (1), and corrected transposition (1). The majority of patients (68%) had reoperation for outgrown or degenerated conduits. In 17 patients, the sternum was opened with a chisel. Two of these patients sustained conduit neointimal collapse from manipulation, and 3 had conduit tear requiring immediate cardiopulmonary bypass through the femoral vessels. In the last 5 patients, the sternum was opened above and below the conduit, and the inner table was chiseled and left attached to the conduit avoiding injury and undue conduit manipulation. Cardiopulmonary bypass and operation were carried out uneventfully. We believe that the recent technique described provides a safe alternative approach to valved conduits adherent to the sternum.
Dynamic QRS-complex and ST-segment monitoring in acute myocardial infarction during recombinant tissue-type plasminogen activator therapy. The TEAHAT Study Group. Changes of the QRS complex are the electrocardiographic expression of irreversible injury of the myocardium. In humans, the process of infarction occurs over several hours. A more rapid development of QRS changes has been reported in patients treated with thrombolytic agents. Patients with strongly suspected acute myocardial infarction (AMI) included in a placebo-controlled trial of 100 mg of recombinant tissue-type plasminogen activator (rt-PA) were monitored for 24 hours with continuous, on-line vectorcardiography. The magnitude of the QRS vector changes correlated with infarct size estimated by the maximal value of lactate dehydrogenase-1 (r = 0.69, p less than 0.001) as well as with left ventricular ejection fraction 30 days after randomization (r = 0.49, p less than 0.001). Treatment with intravenous rt-PA limited total QRS vector change but the QRS vector changes observed occurred more rapidly and reached a plateau 131 minutes earlier in patients treated with rt-PA than in those receiving placebo (p less than 0.01). A certain pattern of highly variable ST vector magnitude was identified and was associated with higher maximal lactate dehydrogenase-1 values (23 +/- 13 vs 14 +/- 10 mu kat/liter, p less than 0.001) and a tendency to higher 1-year mortality (24 vs 9%, p = 0.08) than in patients without this pattern. In patients with this pattern, rt-PA did not affect maximal lactate dehydrogenase-1, time to maximal creatine kinase and final magnitude of QRS vector change.