shukoor65/lab-rag-model huggingface dataset:
Modeling: optimal marathon performance on the basis of physiological factors. This paper examines current concepts concerning "limiting" factors in human endurance performance by modeling marathon running times on the basis of various combinations of previously reported values of maximal O2 uptake (VO2max), lactate threshold, and running economy in elite distance runners. The current concept is that VO2max sets the upper limit for aerobic metabolism while the blood lactate threshold is related to the fraction of VO2max that can be sustained in competitive events greater than approximately 3,000 m. Running economy then appears to interact with VO2max and blood lactate threshold to determine the actual running speed at lactate threshold, which is generally a speed similar to (or slightly slower than) that sustained by individual runners in the marathon. A variety of combinations of these variables from elite runners results in estimated running times that are significantly faster than the current world record (2:06:50). The fastest time for the marathon predicted by this model is 1:57:58 in a hypothetical subject with a VO2max of 84 ml.kg-1.min-1, a lactate threshold of 85% of VO2max, and exceptional running economy. This analysis suggests that substantial improvements in marathon performance are "physiologically" possible or that current concepts regarding limiting factors in endurance running need additional refinement and empirical testing.
Prospective study of alcohol consumption and risk of coronary disease in men. Although an inverse association between alcohol consumption and risk of coronary artery disease has been consistently found in several types of studies, some have argued that the association is due at least partly to the inclusion in the non-drinking reference group of men who abstain because of pre-existing disease. The association between self-reported alcohol intake and coronary disease was studied prospectively among 51,529 male health professionals. In 1986 the participants completed questionnaires about food and alcohol intake and medical history, heart disease risk factors, and dietary changes in the previous 10 years. Follow-up questionnaires in 1988 sought information about newly diagnosed coronary disease. 350 confirmed cases of coronary disease occurred. After adjustment for coronary risk factors, including dietary intake of cholesterol, fat, and dietary fibre, increasing alcohol intake was inversely related to coronary disease incidence (p for trend less than 0.001). Exclusion of 10,302 current non-drinkers or 16,342 men with disorders potentially related to coronary disease (eg, hypertension, diabetes, and gout) which might have led men to reduce their alcohol intake, did not substantially affect the relative risks. These findings support the hypothesis that the inverse relation between alcohol consumption and risk of coronary disease is causal.
EPA in the prevention of restenosis post PTCA. The effect of fish oil on restenosis was evaluated in patients undergoing coronary balloon angioplasty. In addition to routine pharmacotherapy, subjects were given 2.8 g of eicosapentanoic acid (EPA) daily. Treatment was started within twenty-four hours after successful percutaneous transluminal coronary angioplasty (PTCA). After six months of therapy, participants were subjected to coronary arteriography, exercise scintigraphy, exercise electrocardiography, or clinical evaluation. Follow-up evaluation involved 97 coronary lesions in 85 patients. Partial or significant restenosis occurred in 36.5% of patients and 33% of vessels. The presence of severe stenosis before PTCA, dissection, thrombus, multilesion PTCA, and template bleeding time values were not correlated with restenosis. Dilation of the left anterior descending (LAD) and a residual stenosis greater than or equal to 35% were associated with restenosis. Approximately 20% of the patients related difficulty in taking the fish oil. Furthermore, these results show no advantage over expected restenosis rates.
Comparison of CT, low-field-strength MR imaging, and high-field-strength MR imaging. Work in progress. To assess objectively the sensitivity and specificity of low-field-strength (0.064 T) magnetic resonance (MR) imaging, a prospective blind study of 280 examinations was performed to compare low-field-strength MR imaging with computed tomography (CT) and with high-field-strength (1.5-T) MR imaging of the cranium. The sensitivity (defined as the true-positive rate) with high-field MR imaging was superior to that with low-field MR imaging and CT in helping detect overall abnormalities. Sensitivities were generally similar over a broad range of specific cranial central nervous system diseases. Low-field and high-field MR imaging were equivalent in the blind diagnoses of neoplasms and white matter disease, whereas low-field MR and CT were equivalent in the blind diagnoses of contusion, subdural and epidural hematoma, sinus disease, normality, and abnormality. The specificities with low-field MR imaging and CT were substantially better than those with high-field MR imaging.
Effect of breast implants on mammography. We developed an experimental, reproducible method of evaluating the radiographic characteristics of breast implants in vitro using a mammographic phantom and a cadaver. Implant shells tested included smooth silicone, textured silicone, and silicone coated with polyurethane foam. Each type of shell was subsequently filled with saline, silicone gel, and peanut oil; the images were recorded radiographically. Textured silicone and smooth silicone shells minimally impair detection of artifacts. Polyurethane-coated shells are less radiolucent but allow visualization of some microcalcifications. Saline and silicone-gel-filled implants are radiopaque regardless of shell type. Textured silicone and smooth silicone shells filled with peanut oil are radiolucent and allow visualization of microcalcifications and most soft-tissue masses. These data demonstrate that radiolucent breast implants are possible, and further efforts are under way to achieve Food and Drug Administration approval for clinical testing.
The causes and complications of late diagnosis of foreign body aspiration in children. Report of 210 cases. Late diagnoses of foreign body aspiration were defined as occurring beyond 3 days between the aspiration of the foreign body, or onset of symptoms, and correct diagnosis. We reviewed a total of 210 children with late diagnosis of foreign body aspiration. The causes creating late diagnosis of foreign body aspiration in children were as follows: (1) parental negligence (106/210, 50%); (2) misdiagnosis by the fellow professionals and pediatricians (39/210, 19%); (3) the normal chest roentgenographic findings (29/210, 14%); (4) lack of typical symptoms and signs (26/210, 12%); (5) mismanagement (8/210, 4%); and (6) a negative bronchoscopic finding (2/210, 1%). The most common complications encountered were obstructive emphysema (77/186, 41%), mediastinal shift (63/186, 34%), pneumonia (43/186, 24%), and atelectasis (33/186, 18%) in 186 patients who underwent a chest roentgenographic examination. The incidence of major complications was 64% (48/75) in the children who were diagnosed within 4 to 7 days; however, the complication rate was 70% (39/56) in those with a delay in diagnosis of 15 to 30 days, and 95% (20/21) in the cases with a delay in diagnosis of over 30 days after aspirating the foreign bodies.
Hormonal therapy before surgical treatment for uterine leiomyomas. Use of GnRH-A offers a promising medical approach to treating uterine leiomyomas. This therapy can be useful in selected patients, preserving fertility by delaying the need for imminent surgical treatment. In selected perimenopausal women, agonist therapy may, in fact, be an alternative to surgical intervention. Shrinking the size of myomas and reducing uterine volume with these agents have been reported to control symptoms of myoma, making myomectomy or vaginal hysterectomy a safer procedure. Used preoperatively, GnRH-A therapy can also reduce the risk of surgical complications and excessive blood loss.
The effect of ibuprofen on cardiac performance during abdominal aortic cross-clamping. Decreased cardiac output and increased plasma thromboxane have been observed during aortic cross-clamping under general anesthesia. Amelioration of these changes has been reported by preoperative administration of cyclooxygenase inhibitors, but heterogeneity in patients' intravascular volume status has confounded analysis of the drugs' effects in previous studies. We studied hemodynamic conditions in 24 volume-loaded (pulmonary capillary wedge pressure greater than 10 mm Hg) patients undergoing abdominal aortic aneurysm repair under general plus epidural anesthesia, after preoperative double-blind administration of either ibuprofen 800 mg (n = 12) or placebo (n = 12). The hemodynamic response to aortic cross-clamping was similar in both groups. Pulse and mean arterial pressure remained unchanged; cardiac index decreased after aortic cross-clamping from 2.4 +/- 0.1 (mean +/- standard error of the mean [SEM]) to 2.1 +/- 0.1 1/min/m2 in the ibuprofen group and from 2.5 +/- 0.1 to 2.3 +/- 0.2 1/min/m2 in the placebo group (p less than 0.01 versus preclamp values in both groups, multivariate analysis of variance [MANOVA]), but improved after declamping. Both left and right ventricular stroke work indexes followed a similar pattern. Plasma 6-keto prostaglandin Fl alpha (6-k-PGF1 alpha) increased transiently from a baseline level of 304 +/- 44 to 2083 +/- 698 pg/ml plasma in mixed venous blood 30 minutes after incision in the placebo group (p less than 0.05), but no other significant change in plasma 6-keto prostaglandin Fl alpha or in thromboxane B2 occurred in either group at any other time.
Rib fractures complicating median sternotomy. The postoperative chest radiographs of 100 consecutive patients undergoing median sternotomy were reviewed for the presence of acute rib fractures. The majority of patients underwent coronary artery bypass grafting. Thirteen patients sustained 15 fractures. Eleven of these fractures were of the left first rib and 7 of the 15 fractures occurred at the costotransverse articulation. The fractures tended to be subtle on the postoperative portable chest radiographs and were initially overlooked in 4 patients. Heavier patients and those with larger body surface areas were more susceptible to the development of fractures. There was no statistical correlation to total operating time, bypass time, or global ischemic time.
Evaluating genetic association among ovarian, breast, and endometrial cancer: evidence for a breast/ovarian cancer relationship. The possibility of a genetic relationship between ovarian, breast, and endometrial cancer was investigated in data from a large multicenter, population-based, case-control study, the Cancer and Steroid Hormone Study conducted by the Centers for Disease Control (CDC). Age-adjusted relative risks (RRs) for mothers and sisters of 493 ovarian cancer cases, 895 breast cancer cases, and 143 endometrial cancer cases versus 4,754 controls were calculated. Significantly elevated age-adjusted RRs were found for ovarian cancer (RR = 2.8; 95% confidence interval [CI] = 1.6-4.9) and breast cancer (RR = 1.6; 95% CI = 1.1-2.1) among relatives of ovarian cancer probands and for breast cancer (RR = 2.1; 95% CI = 1.7-2.5) and ovarian cancer (RR = 1.7; 95% CI = 1.0-2.0) among relatives of breast cancer probands. Relatives of endometrial cancer probands had an elevated RR for endometrial cancer only (RR = 2.7; 95% CI = 1.6-4.8). The genetic relationship between ovarian, breast, and endometrial cancer was tested using a multivariate polygenic threshold model developed by Smith (1976), which was modified to accommodate three classes of probands. Estimates of heritability for ovarian, breast, and endometrial cancer were 40%, 56%, and 52%, respectively. There was a significant genetic correlation between ovarian and breast cancer (R12 = .484). Evidence for significant genetic overlap between endometrial cancer and either ovarian or breast cancer was not found. These results suggest the existence of a familial breast/ovarian cancer syndrome. Endometrial cancer, while heritable, appears to be genetically unrelated.
The safety and efficacy of terazosin in the treatment of essential hypertension in blacks. Terazosin, a new selective alpha 1-adrenergic receptor antagonist, has been found to be an effective antihypertensive agent. In a series of studies, the safety and efficacy of terazosin, alone and in combination with other antihypertensive agents, were evaluated in 1180 black patients with mild to moderate essential hypertension. Terazosin was effective in lowering blood pressure when administered alone (in dosages of 1 to 80 mg/day) and when prescribed (in dosages of 1 to 20 mg/day) in combination with other antihypertensive agents. In elderly black patients, terazosin, 1 to 10 mg daily, was as effective in lowering blood pressure as propranolol (40 to 120 mg twice daily). Changes (mean +/- SE) in sitting diastolic blood pressure from baseline were -8.1 +/- 1.4 mm Hg for terazosin and -5.0 +/- 1.5 mm Hg for propranolol. Terazosin (5 mg) combined with methyclothiazide (2.5 to 5 mg) produced a significantly greater (p less than 0.01) antihypertensive effect than that of terazosin alone. Changes (mean +/- SE) in standing diastolic blood pressure from baseline were -7.9 +/- 2.0 mm Hg for terazosin alone, -15.1 +/- 2.1 mm Hg for terazosin plus 2.5 mg of methyclothiazide, and -15.0 +/- 2.0 mm Hg for terazosin plus 5 mg of methyclothiazide. Terazosin had a favorable effect on serum lipid levels and appeared to compensate for the negative lipid effects associated with diuretics and beta-blockers when used in combination with these agents. Terazosin, alone and combined with other antihypertensive agents, was well tolerated with minimal side effects in black hypertensive patients.
Superficial thrombophlebitis diagnosed by duplex scanning. Since July 1982, this noninvasive vascular laboratory has performed 12,856 lower extermity venous duplex examinations. All cases of acute venous thrombosis have been categorized and entered into a computer data base. One thousand four hundred twelve examinations were positive for acute venous thrombosis. This report analyzes the laboratory's entire experience with superficial thrombophlebitis (SVT). One hundred eighty-six patients were diagnosed by duplex scanning to have SVT. Women outnumbered men 99 to 87. They were slightly older (average age 58.4 +/- 16.2 years) compared with the men (53.8 +/- 14.2 years). Men were more likely to have a complicated course of SVT (40% vs 22%; p less than 0.01). Complications included either radiographically documented pulmonary embolism or deep venous involvement. Fifty-seven (31%) patients had at least one complication of SVT. A series of predisposing factors was analyzed and six factors were associated with an increased risk of complications. They are bilateral SVT (p less than 0.01), age greater than 60 years (p less than 0.01), male sex (p less than 0.01), history of deep venous thrombosis (p less than 0.01), bed rest (p less than 0.02), and presence of infection (p less than 0.02). Location of thrombus within the greater saphenous vein (35%) was most likely to be associated with complications. Isolated varicosities (8%) were least likely to be associated with complications. Duplex scanning identifies a significant number of complications of patients with SVT and should be obtained in cases of saphenous vein involvement or in the presence of associated risk factors.
Effect of Candida albicans plus histamine on prostaglandin E2 production by peripheral blood mononuclear cells from healthy women and women with recurrent candidal vaginitis. The in vitro production of prostaglandin E2 (PGE2) by peripheral blood mononuclear cells (PBMC) in response to viable Candida albicans, histamine, and C. albicans plus histamine was examined. With PBMC from 10 healthy women, C. albicans but not histamine induced PGE2 at a low level (100 pg/ml). However, C. albicans plus histamine acted synergistically to stimulate PGE2 production (448 pg/ml). PBMC from 8 of 10 women with recurrent candidal vaginitis also produced maximal levels of PGE2 in the presence of C. albicans plus histamine. Production of tumor necrosis factor by PBMC from patients and controls was unaffected by histamine in both the presence and absence of C. albicans. However, unlike the controls, PBMC from six of the patients who were atopic and from two nonatopic patients spontaneously released PGE2 in vitro. Addition of 4 or 10 units/ml interferon-gamma inhibited spontaneous and C. albicans-induced PGE2 production by PBMC. These data reinforce the evidence that immediate hypersensitivity responses may be involved in the etiology of recurrent candidal vaginitis.
Trunk orientation as the determining factor of the 'contralateral' deficit in the neglect syndrome and as the physical anchor of the internal representation of body orientation in space. The present study examines which egocentric coordinate system determines the border between the disturbed 'contralateral' and the normal 'ipsilateral' side in patients with hemineglect. Based on the observation of significantly longer reaction times for saccades towards stimuli presented in the left visual field (LVF) in right brain-damaged patients with hemineglect, stimuli were presented randomly to the LVF or RVF and the corresponding saccadic reaction times (SRTs) were compared. Beginning with the standard body position generally used for the investigation of neglect patients, where the midlines of head, trunk and visual field are parallel and oriented straight towards the middle of the projection screen, the spatial relation between orientation of head and trunk midlines and location of the target stimuli was systematically varied while holding the retinal projection of the stimuli constant. The deficit in SRTs towards the LVF in 4 right brain-damaged patients with left-sided hemineglect could be compensated for by turning the patients' trunk to the left, such that both LVF and RVF-stimuli were projected to the right, ipsilateral side of trunk space. The results suggest that the spatial orientation of the trunk midline divides our normal perception of space into an egocentric 'left' and an egocentric 'right' sector and seems to be the decisive factor for determining the neglected 'contralateral' part of space in patients with brain-damage. They indicate that the trunk midline constitutes the physical anchor for calculation of the internal egocentric coordinate frame for representing body position with respect to external objects. The hypothesis of Ventre et al. (1984) that deficient reactions to contralaterally located stimuli in neglect patients could be the result of a displacement of these egocentric coordinates towards the non-neglected, ipsilateral side is discussed.
Perioperative stroke. Part II: Cardiac surgery and cardiogenic embolic stroke. The major mechanism of stroke in cardiac surgery is embolization. The risk is higher in intracardiac than in extracardiac surgery. The incidence of stoke associated with CABG is about 5%. The cerebral protective properties of isoflurane and thiopentone, acid-base management, and monitoring of cerebral perfusion during cardiopulmonary bypass are discussed. Prophylactic carotid endarterectomy for patients with asymptomatic carotid disease before cardiac surgery is not necessary. Symptomatic carotid disease increases the risk of stroke, and the management of patients who have both symptomatic coronary and carotid artery diseases is discussed. Cardiogenic embolism is probably responsible for many perioperative strokes. Patients with atrial fibrillation, valvular disease, and prosthetic heart valves are at high risk of cardiogenic embolism. Strokes associated with cardioversion, pacemaker insertion, coronary arteriography and angioplasty are explored.
Chemotherapy of metastatic and/or recurrent undifferentiated nasopharyngeal carcinoma with cisplatin, bleomycin, and fluorouracil. Undifferentiated nasopharyngeal carcinoma (UCNT) is known to be radiosensitive and chemosensitive, but the latter has never been studied prospectively with phase II methodology. After an intensive work-up, 49 patients with recurrent (REC) and/or metastatic (MTS) UCNT were treated with three monthly cycles of cisplatin (CDDP) 100 mg/m2 day 1; bleomycin 15 mg intravenously (IV) day 1, and 16 mg/m2/d continuous infusion (CI) days 1 to 5; and fluorouracil (5FU) 650 mg/m2/d CI days 1 to 5 (PBF). Of the 49 patients, 33 were North African. The sex ratio was three males:one female, and the median World Health Organization (WHO) performance status was 1.6. In the 48 patients assessable for response, we observed nine (19%) complete responses (CRs) and 29 (60%) partial responses (PRs) (60%), for a 79% overall response rate (95% confidence interval, 68% to 90%) in the assessable group and a 78% global rate. There were eight CRs (24%) observed in the group without previous chemotherapy (33 patients) compared with one CR in the chemotherapy pretreated group (16 patients). Four patients are still alive without evidence of disease after 52+, 54+, 58+, and 58+ months, respectively. All of them had less than three bone MTS sites, and received radiation therapy in these sites. The results confirm the chemosensitivity of UCNT, and the observation of unmaintained long-term responders makes curability a possible consideration.
Effect of denervation or unweighting on GLUT-4 protein in rat soleus muscle. The purpose of this study was to test the hypothesis that the decreased capacity for glucose transport in the denervated rat soleus and the increased capacity for glucose transport in the unweighted rat soleus are related to changes in the expression of the regulatable glucose transporter protein in skeletal muscle (GLUT-4). One day after sciatic nerve sectioning, when decreases in the stimulation of soleus 2-deoxyglucose (2-DG) uptake by insulin (-51%, P less than 0.001), contractions (-29%, P less than 0.05), or insulin and contractions in combination (-40%, P less than 0.001) were observed, there was a slight (-18%, NS) decrease in GLUT-4 protein. By day 3 of denervation, stimulation of 2-DG uptake by insulin (-74%, P less than 0.001), contractions (-31%, P less than 0.001), or the two stimuli in combination (-59%, P less than 0.001), as well as GLUT-4 protein (-52%, P less than 0.001), was further reduced. Soleus muscle from hindlimb-suspended rats, which develops an enhanced capacity for insulin-stimulated glucose transport, showed muscle atrophy similar to denervated soleus but, in contrast, displayed substantial increases in GLUT-4 protein after 3 (+35%, P less than 0.05) and 7 days (+107%, P less than 0.001). These results indicate that altered GLUT-4 expression may be a major contributor to the changes in insulin-stimulated glucose transport that are observed with denervation and unweighting. We conclude that muscle activity is an important factor in the regulation of GLUT-4 expression in skeletal muscle.