shukoor65/lab-rag-model huggingface dataset:
Acid perfusion test and 24-hour esophageal pH monitoring with symptom index. Comparison of tests for esophageal acid sensitivity. The acid perfusion (Bernstein) test and esophageal pH monitoring are the two most popular tests for identifying esophageal acid sensitivity in difficult cases of reflux disease. Therefore, we prospectively compared these test results in 75 consecutive noncardiac chest pain patients who had both an acid perfusion test and chest pain during 24-hr pH testing. A positive acid perfusion test was defined by the replication of the patient's typical chest pain twice by the acid infusion. Esophageal pH testing identified abnormal amounts of acid reflux and correlated symptoms with acid reflux--the "symptom index." Fifteen patients (20%) had a positive acid perfusion test while 45 patients (59%) had a positive symptom index (range 6-100%). Only 9/34 (26%) patients with abnormal reflux had a positive acid perfusion test. Although it had excellent specificity (83-94%), the acid perfusion test had poor sensitivity (32-46%) when compared to the symptom index regardless of the percent positive cutoff level. The best positive predictive value for the acid perfusion test was 87%, but this occurred when the test sensitivity was 32%. Modifying the end point of a positive acid perfusion test to include heartburn improves the sensitivity (52-67%) while markedly compromising specificity and positive predictive value. Thus, esophageal pH monitoring correlating symptoms with acid reflux is superior to the acid perfusion test for identifying an acid sensitive esophagus in patients with noncardiac chest pain.
Acute infectious erythemas in children: a clinico-microbiological study. One-hundred children with an acute illness comprising fever and widespread erythematous rash were prospectively studied to determine whether clinical presentations are helpful in defining the causative agent and to identify the most appropriate microbiological specimens. An infectious agent was identified in 65 children; 72% were viruses, 20% were bacteria, 5% were Mycoplasma pneumoniae and in 3% both viruses and bacteria were detected. The most common infectious agents were picornaviruses, an atypical presentation of measles and Group A beta-haemolytic Streptococcus. Different patterns of rash occurred with each of these infections. The clinical presentation of a child with an acute febrile illness and rash was unhelpful in defining the causative agent. Routine management should include a throat swab for bacterial investigation and in selected cases a blood sample for IgM viral titres.
Serum cholesterol concentration and coronary heart disease in population with low cholesterol concentrations. OBJECTIVE--To examine the relation between serum cholesterol concentration and mortality (from coronary heart disease and from other causes) below the range of cholesterol values generally seen in Western populations. DESIGN--Prospective observational study based on 8-13 years of follow up of subjects in a population with low cholesterol concentrations. SETTING--Urban Shanghai, China. SUBJECTS--9021 Chinese men and women aged 35-64 at baseline. MAIN OUTCOME MEASURE--Death from coronary heart disease and other causes. RESULTS--The average serum cholesterol concentration was 4.2 mmol/l at baseline examination, and only 43 (7%) of the deaths that occurred during 8-13 years of follow up were attributed to coronary heart disease. There was a strongly positive, and apparently independent, relation between serum cholesterol concentration and death from coronary heart disease (z = 3.47, p less than 0.001), and within the range of usual serum cholesterol concentration studied (3.8-4.7 mmol/l) there was no evidence of any threshold. After appropriate adjustment for the regression dilution bias, a 4 (SD 1)% difference in usual cholesterol concentration was associated with a 21 (SD 6)% (95% confidence interval 9% to 35%) difference in mortality from coronary heart disease. There was no significant relation between serum cholesterol concentration and death from stroke or all types of cancer. The 79 deaths due to liver cancer or other chronic liver disease were inversely related to cholesterol concentration at baseline. CONCLUSION--Blood cholesterol concentration was directly related to mortality from coronary heart disease even in those with what was, by Western standards, a "low" cholesterol concentration. There was no good evidence of an adverse effect of cholesterol on other causes of death.
The value of tests predicting renovascular hypertension in patients with renal artery stenosis treated by angioplasty. The aim of this study was to evaluate tests predicting renovascular hypertension. This was done by relating the results of renal vein renin tests, the captopril test, and renal scintigraphic tests to the blood pressure outcome 12 months after relief of renal artery stenosis by percutaneous transluminal renal angioplasty in 31 patients. Cure was seen in eight (26%). Improved blood pressure was obtained in 12 patients (39%), and in 11 patients (35%), the result for blood pressure was a failure. The accuracies of the two mathematical models used to analyze the renal vein renin assays were 44% and 60%. The captopril test showed a sensitivity of 36% and an accuracy of 43%. Renal captopril technetium Tc 99m-labeled pentetic acid scintigraphy gave a sensitivity of 60%. Stepwise logistic regression analysis of clinical variables in relation to blood pressure response revealed age as the only factor significantly related to blood pressure outcome. We conclude that the tests used are unfit for helping select patients for percutaneous transluminal renal angioplasty and that age may have an important influence on outcome.
Surgical approaches to congenital atresia of the external auditory canal. During the past 4 years, 22 patients with congenital atresia of the external auditory canal underwent 24 initial operations by either an anterior or transmastoid approach. No attempt at randomization was made, but the two groups were similar in number and pathology (in 14 cases approach was anterior and in 10 cases approach was transmastoid). Followup ranged from 6 months to 4 years. Hearing results were similar in the two groups (71% with air-bone gap less than 30 dB). There were no instances of facial nerve injury or sensorineural hearing loss. Facial nerve monitoring was used. Complications of stenosis and drainage were more common with the transmastoid approach. In both groups, hearing results were accomplished with the patients' intact ossicles or prosthetic reconstructions. Meticulous soft-tissue technique, with split-thickness grafts covering all exposed bone, is the key to preventing stenosis. For the three cases of patients with thick, acellular atresia plates, a different approach was developed. Maintaining proper orientation during the medial dissection is more difficult in these cases. By opening the antrum primarily and identifying the lateral canal, ossicles, and facial nerve, an ear canal can then be created anteriorly with these landmarks in view. An intact canal wall-like procedure is carried out. Although hearing results are similar, the anterior approach, because of fewer postoperative complications, is now our procedure of choice. Proper orientation and soft-tissue technique are the keys to successful correction of the congenitally atretic ear canal.
Hypoxic exposure and activation of the afterdischarge mechanism in conscious humans. After voluntary hyperventilation, normal humans do not develop a significant ventilatory depression despite low arterial CO2 tension, a phenomenon attributed to activation of a brain stem mechanism referred to as the "afterdischarge." Afterdischarge is one of the factors that promote ventilatory stability. It is not known whether physiological stimuli, such as hypoxia, are able to activate the afterdischarge in humans. To test this, breath-by-breath ventilation (VI) was measured in nine young adults during and immediately after a brief period (35-51 s) of acute hypoxia (end-tidal O2 tension 55 Torr). Hypoxia was terminated by switching to 100% O2 (end-tidal O2 tension of first posthypoxic breath greater than 100 Torr). Brief hypoxia increased VI and decreased end-tidal CO2 tension. In all subjects, termination of hypoxia was followed by a gradual ventilatory decay; hyperoxic VI remained higher than the normoxic baseline for several breaths and, despite the negative chemical stimulus of hyperoxia and hypocapnia, reached a new steady state without an apparent undershoot. We conclude that brief hypoxia is able to activate the afterdischarge mechanism in conscious humans. This contrasts sharply with the ventilatory undershoot that follows relief of sustained hypoxia, thereby suggesting that sustained hypoxia inactivates the afterdischarge mechanism. The present findings are of relevance to the pathogenesis of periodic breathing in a hypoxic environment. Furthermore, brief exposure to hypoxia might be useful for evaluation of the role of afterdischarge in other disorders associated with unstable breathing.
Celiac axis and superior mesenteric artery injury associated with left radical nephrectomy for locally advanced renal cell carcinoma. The superior mesenteric artery and celiac axis were inadvertently ligated during left radical nephrectomy for a large upper pole renal carcinoma with massive perihilar and periaortic adenopathy. Computer-generated 3-dimensional illustrations created from the computerized tomography scan demonstrated the close proximity between these visceral branches and the adenopathy mass complex, and showed how this bulky disease may interfere with surgical anatomy. When left radical nephrectomy is performed for locally advanced and/or bulky node-positive renal neoplasms, surgeons must be cognizant of the location of the major visceral arterial branches and possible anatomical distortions.
Effects of a minimally supervised exercise program for mentally retarded adults. Previous exercise studies that attempted to improve the cardiovascular fitness (CVF) of mentally retarded (MR) adults were flawed with methodological shortcomings that prevented conclusive results. At issue in these training studies were fitness test validity and reliability, exactness of duration and intensity of training, and an inordinate amount of supervision. Therefore, we sought to determine whether moderately MR adults (seven males, five females; IQ = 61 +/- 3, age = 25 +/- 3 yr) could improve their CVF through a minimally supervised 16-wk training program. Each subject repeated exercise tests twice on two different modes of exercise, the treadmill (TM) and Schwinn Air-Dyne ergometer (SAE), before training to ensure validity and reliability of initial CVF levels. Intensity and frequency of exercise were closely monitored. An observer was present during the training bouts, but, following initial instructions, no additional encouragement or instructions were given. Although the training program significantly increased peak VO2 (29.2 +/- 8 to 33.5 +/- 9 ml.kg-1.min-1) and peak ventilation (73 +/- 26 to 81 +/- 231.min-1) when assessed on the TM, significant changes in these same parameters were not seen when assessed on the SAE. The importance of these results was discussed.
Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up The perioperative and follow-up results of cardiac operations employing extracorporeal circulation and cold cardioplegic arrest were examined in 191 consecutive patients greater than or equal to 80 years of age having surgery over a 5 year period (1982 to 1986). Most patients had severe preoperative symptoms with functional class III (39.8%) or IV (57.1%) limitation. The overall 30 day postoperative cardiac mortality rate was 15.7%. The total in-hospital mortality rate was 18.8%; the mean postoperative hospital stay was 16.4 +/- 13.3 days. The perioperative mortality rate for elective operations was as follows: coronary artery bypass (5.6%), aortic valve replacement (9.6%), aortic valve replacement with coronary bypass (17.9%) and mitral valve surgery with or without coronary bypass (21.4%). Urgent operations were performed in 39 patients (20.4%) with a total perioperative mortality rate of 35.9%; urgent coronary artery bypass was performed in 26 patients (67%) with an in-hospital mortality rate of 23.1%. Clinical evidence of left ventricular failure, functional class IV symptoms, left ventricular ejection fraction less than 50%, mitral valve repair or replacement for severe mitral regurgitation and urgent operation were associated with an increased perioperative mortality rate. Follow-up study in all 155 patients surviving postoperative hospitalization at 22.6 +/- 14.8 months showed significant improvement in symptom status in all surgical subgroups. There were 18 follow-up deaths (11.6%); 10 were noncardiac. The actuarial survival rate of the entire study group was significantly better than that in age- and gender-matched control subjects (p = 0.037).
Interethnic differences in pain perception. While several investigators have reported relationships between ethnic background and expression of pain, such relationships are in fact highly problematical. Few studies of pain and ethnicity have used quantitative measures of pain combined with multivariate methods of data analysis. Most have focussed on populations which, unlike many in the United States today, are characterized by highly distinct ethnic groups. The study reported here interviewed 536 persons recently treated for forms of cancer known to cause significant pain. Pain was assessed using standard, well validated instruments, including Graphic Rating Scales anchored in several alternative time-frames and the McGill Pain Questionnaire. The study took place in an area with a low proportion of recent immigrants and only small concentrations of distinct ethnic minorities. No statistically significant relationships were observed between ethnic identity and measures of pain sensation. However, pain described in affective terms according to the McGill Pain Questionnaire did vary among ethnicities. This observation suggests that cultures associated with specific ethnic identities still condition individual expression of pain despite the high degree of assimilation that has occurred among ethnic groups in the United States.
The role of platelet activating factor and its antagonists in shock, sepsis and multiple organ failure. PAF has been implicated as a mediator of shock, sepsis and MOF. The results of experimental data demonstrate that PAF induces changes characteristic of endotoxemia and sepsis, including systemic hypotension and diffuse microvascular leakage. These effects are prevented by PAF antagonists. PAF induces many of the characteristic changes of MOF, including functional impairment in the lung, kidney, gastrointestinal tract and heart. PAF antagonists will inhibit these adverse effects. PAF antagonists are now being manufactured by a number of pharmaceutical companies studying the beneficial effects of PAF antagonists in human disease. Data from these studies promise valuable information with significant clinical relevance to the practicing surgeon.
A comparison of tocopherol and tocotrienol for the chemoprevention of chemically induced rat mammary tumors. Two forms of vitamin E, tocopherol and tocotrienol, were tested for chemopreventive activity in two chemically induced rat mammary-tumor models. When mammary tumors were induced by 7,12-dimethylbenz(a)anthracene (DMBA, 50 mg/kg), only the tocotrienol group had a statistically significant increase in tumor latency. There was no effect of either compound on tumor multiplicity. When tumors were induced by N-nitrosomethylurea (NMU, 30 mg/kg), neither analogue of vitamin E modified latency, whereas tocotrienol increased tumor multiplicity. In summary, neither vitamin analog had a major impact on mammary-tumor development after tumor induction with either DMBA or NMU.
Increased negative inotropic effect of calcium-channel blockers in hypertrophied and failing rabbit heart. The effects on ventricular function of calcium channel blockers and isoproterenol were studied in isovolumically beating perfused control rabbit hearts and in hearts subjected to a double pressure plus volume overload studied at the early phase of heart failure. In control hearts, isoproterenol produced an increase of systolic ventricular function and relaxation that was maximal at 10(-7) M. In failing hearts, inotropic state increase in response to isoproterenol was significantly smaller (P less than .01) with no observed lusitropic effect. In control hearts, verapamil and diltiazem produced dose-dependent decreases of ventricular function which were larger with verapamil than with diltiazem (median drug concentration50 of developed pressure was, respectively, 1163 +/- 131 nM and 4524 +/- 451 nM, P less than .001). In failing hearts, contractility decrease was larger than in control hearts (median drug concentration50 of developed pressure was 604 +/- 69 nM and 2691 +/- 580 nM with verapamil and diltiazem, respectively). In contrast, Ro 40-5967, a new calcium-channel blocker, did not produce reductions of inotropic state with concentrations up to 10(-5) M. All three calcium-channel blockers produced a 2-fold increase of coronary flow at 10(-6) M. We conclude that the deleterious effect of verapamil and diltiazem in heart failure is due, at least in part, to a direct depressant effect of these drugs on contractility, which is larger than in control hearts. Additionally, the in vivo sympathetic compensation is probably reduced, as indicated by the decreased ventricular responsiveness to isoproterenol.
Heart transplantation in children: an international survey. A survey of cardiac transplantation in children provided data from 381 transplantations in 362 patients from 32 centers in the United States and ten international centers. The number of transplantations continues to increase, in part because of transplantations in infants with hypoplastic left heart syndrome and patients with congenital defects. The immunosuppression regimens were more uniform than in the 1985 survey, and triple therapy was most common. Actuarial survival rates were 85% at 1 month, 72% at 1 year, 64% at 3 years, and 60% at 5 years. However, these improved rates are still not equal to the survival of the overall cardiac transplant population, in part because of lower survival rates in neonates. Ventricular dysfunction and rejection, rather than infection, were the leading causes of death. Rejection and infection were the most frequent complications. Also common were hypertension (39%) and seizures (25%), whereas coronary artery disease (8%) was unusual. Functional results were excellent in 85%, and only 7% were disabled. Questions concerning growth rates and many other aspects cannot yet be answered. However, it is apparent that cardiac transplantation in the pediatric population is a very worthwhile endeavor.
Practical phlebology. Sclerotherapy of large veins. A practical, step-by-step guide for the sclerotherapy of large varicose veins is offered. First, an orientation regarding the place of sclerotherapy and surgery in the total treatment of varicose veins is given, with a practical clinical classification of varicose veins. This is followed by a detailed discussion of patient education before sclerotherapy, material to be used with recommended concentrations, injection technique, compression after sclerotherapy, instructions to the patient after injection, and procedures at subsequent visits.
Nuclear magnetic resonance spectroscopy study of human brain after cardiac resuscitation. We used 31P nuclear magnetic resonance spectroscopy to study the cerebral metabolic function of eight patients with severe postischemic anoxic encephalopathy secondary to cardiac arrest. Spectroscopy was performed at 18 +/- 13 and 64 +/- 20 hours after resuscitation. Glasgow Coma Scale scores at the time of initial and repeat spectroscopy were 3.6 +/- 1.2 and 3.5 +/- 1.2, respectively. In those patients whose spectra were of adequate quality to monitor pH, all demonstrated tissue alkalosis in at least one brain region. The mean brain pH at initial spectroscopy was 7.14 +/- 0.09 and was significantly alkalotic when compared with age- and sex-matched normal controls (pH = 6.98 +/- 0.04, p less than 0.0001). Five of the eight patients showed at least one region of persistent alkalosis at repeat spectroscopy, whereas one patient demonstrated severe acidosis with a pH of 6.42. Spectra demonstrated marked metabolic heterogeneity, ranging from normal in appearance to complete obliteration of all high-energy phosphates with only inorganic phosphate remaining.
Supraciliary hemangiopericytoma. A 10-year-old black girl complaining of pain and decreased vision in the left eye was found to have a smoothly elevated ciliochoroidal mass involving the superonasal quadrant of the left eye. The mass appeared circumscribed and uniformly dense by computed tomography. The tumor was hyperintense to vitreous and cerebral white matter on T1-weighted magnetic resonance imaging but was hypointense to vitreous and hyperintense to white matter on T2-weighted magnetic resonance imaging. Results of gross examination of the enucleated eye showed a sharply circumscribed, tan, intraocular mass arising equatorially. Results of histopathologic examination showed a well-vascularized spindle cell proliferation with a sinusoidal pattern characteristic of hemangiopericytoma. This is the third reported case of intraocular hemangiopericytoma and the first in a pediatric patient.
Problems in the definition and treatment of early gastric cancer. Radical operation with extensive dissection of lymph nodes (R1, 48 patients; R2, 196 patients; R3, one patient) was performed in 245 out of 247 patients with early gastric cancer. The 5-year survival rate was only 73.2 per cent in the 34 patients with lymph node metastases (31.8 per cent). Analysis of factors influencing recurrence revealed that not only lymph node metastases but also the depth of cancer invasion could affect prognosis in early gastric cancer. This study suggests that radical operation with complete dissection of the first and second group of lymph nodes (R2 resection) is a safe and appropriate treatment even for early gastric cancer. We propose that the definition of early gastric cancer be modified to 'carcinoma with invasion confined to the mucosa or submucosa and without evidence of lymph node metastases'.
Resection of residual mediastinal germ cell masses with the Cavitron ultrasonic surgical aspirator. Residual mediastinal masses after chemotherapy for germ cell tumors should be resected. Complete excision of bulky residual masses may sometimes be difficult because of problems with exposure in the region of the great vessels and important nerves. Two cases are presented in which the Cavitron ultrasonic surgical aspirator (Valleylab Inc., Surgical Systems Division, Stamford, Conn.) facilitated excision of large masses after intensive chemotherapy. We found that the collapsed pseudocapsule remaining after aspiration of tumor mass allowed early improved exposure and safer dissection from neighboring vessels and neural structures. Complete excisions were accomplished and no viable tumor was found, so that the patients were spared the immediate need for further therapy. Both had uneventful recoveries.