123rc/medical_text huggingface dataset:
Cerebral venous oxygen content as a measure of brain energy metabolism with increased intracranial pressure and hyperventilation. In order to test the hypothesis that the cerebral arteriovenous oxygen difference (AVDO2) and venous oxygen content (VO2) could be used to monitor brain energy metabolism in the setting of increased intracranial pressure (ICP). 12 cats were studied with 31P-magnetic resonance spectroscopy. six cats were subjected to intracranial hypertension by cisternal infusion of saline. Energy failure occurred at an average AVDO2 of 8.4 +/- 3.2 vol% (+/- standard deviation) (range 4.7 to 14.7 vol%). The VO2 at the point of metabolic failure averaged 1.45 +/- 0.6 vol% and extended over a narrower range (1.0 to 2.9 vol%). In an additional six cats, ICP was raised to the threshold of metabolic failure and hyperventilation was then instituted (pCO2 10 to 18 torr). Five of the six cats experienced a drop in VO2 with hyperventilation. In two of these animals, hyperventilation resulted in a VO2 of 1.1 vol% or less and in metabolic failure as evidenced by a fall in phosphocreatine. It is concluded that a VO2 of less than 2 vol% is correlated with brain ischemia and that the safety of hyperventilation in the setting of increased ICP can be monitored by the use of VO2.
Cerebral glucose utilization during sleep in Landau-Kleffner syndrome: a PET study. Three right-handed male children (aged 5, 6, and 11 years) with signs, symptoms and/or history of the syndrome of acquired aphasia-epilepsy (Landau-Kleffner syndrome) were studied during drug-induced, electroencephalographically (EEG)-monitored sleep by positron-emission tomography (PET) and the [18F]fluorodeoxyglucose (FDG) method. Our data demonstrate that in Landau-Kleffner syndrome, cerebral glucose utilization is not normal during sleep. The metabolic pattern varied between the children but the metabolic disturbances always predominated over the temporal lobes. They were right-sided, left-sided, or bilateral. In the two first patients, EEG recordings showed continuous spike-and-wave discharges during sleep and a right-greater-than-left asymmetry was observed in temporal areas. In patient 1, the asymmetry was associated with a relative increase of glucose utilization of the right posterior temporal region. In patient 2, the glucose utilization was relatively decreased in the left anterotemporal and left perisylvian regions. In patient 3, the sleep EEG showed no discharge and no significant asymmetry was observed; however, glucose utilization of both temporal lobes was decreased. Lower metabolic rates in subcortical structures than in cortex were also noted in the three children. This metabolic pattern may be related to the maturation of the central nervous system (CNS).
Assessment of the biliary tract after liver transplantation: T tube cholangiography or IODIDA scanning. Biliary tract obstruction or anastomotic leakage are common problems following liver transplantation. In a sequential study, 31 patients with a liver transplant were investigated by 99mTc-IODIDA (IODIDA) scanning and T tube cholangiography (TTC) and the results were compared with clinical outcome. Seven patients had an extrahepatic biliary obstruction and one patient had a biliary leak. In the detection of biliary complications TTC and IODIDA scanning were similar in terms of sensitivity (63 per cent for both) but TTC had a better specificity (79 per cent versus 60 per cent) and accuracy (74 per cent versus 60 per cent) than IODIDA scanning. When liver function was taken into account, the diagnostic efficacy of both tests in patients with bilirubin levels of less than 200 mumol/l was similar. With levels greater than 200 mumol/l there was a greater number of false positive results with IODIDA scanning (12 per cent versus 54 per cent). The only significant biliary leak was clearly detected by TTC but not IODIDA scanning. TTC remains the more effective way of evaluating the biliary tract after transplantation. IODIDA scanning has limited value when bilirubin levels are elevated, but may provide additional information about blood supply, hepatocyte function and intrahepatic cholestasis.
Neurologic complications of the tryptophan-associated eosinophilia-myalgia syndrome. A case of tryptophan-associated eosinophilia, central nervous system complications, and multiple white matter lesions by magnetic resonance imaging is presented. Eosinophilia regardless of its cause should be included within the differential of patients exhibiting periventricular white matter lesions.
Cardiac rhythm disturbances early after orthotopic heart transplantation: prevalence and clinical importance of the observed abnormalities. To precisely define the incidence, type and consequences of cardiac arrhythmias early after heart transplantation, 25 cardiac transplant recipients were monitored continuously for 728 days from the day of surgery to discharge or death. A subset of 15 patients had sinus node function studies with overdrive suppression performed weekly at the time of endomyocardial biopsy. Results revealed sinus bradycardia in 10 patients (40%) and junctional bradycardia in 6 (24%). Supraventricular tachycardia in the form of atrial tachycardia, atrial fibrillation and atrial flutter occurred in 11 patients (44%). Ventricular tachycardia occurred in 15 patients (60%) and was nonsustained in all. Cardiac pacing for 1,403 h was used in nine patients with a pulse rate less than 50 beats/min; seven recovered and permanent pacing was instituted in two. In the subgroup that had sinus node function studies, seven patients were identified with clinical bradyarrhythmia; each had abnormal sinus node recovery time (greater than 1,400 ms) and abnormal corrected sinus node recovery time (greater than 525 ms) in at least one study. These seven patients also had a significantly prolonged ischemic time (236 +/- 26 versus 159 +/- 68 min, p less than 0.01). In conclusion, cardiac arrhythmias, particularly ventricular tachycardia and bradyarrhythmia, occur more commonly early after orthotopic heart transplantation than has previously been reported. Sinus node dysfunction due to prolonged organ ischemic time, antiarrhythmic drug use or surgical trauma, alone or in combination, may contribute to these arrhythmias.
Vector short-latency somatosensory-evoked potentials after median nerve stimulation. A new method has been developed for recording short-latency somatosensory-evoked potentials after median nerve stimulation. Negative electrical forces recorded with three orthodiagonal bipolar electrodes in the neck had a direction opposite to that of impulse conduction in the proximal peripheral and cervical somatosensory pathway. Sequential tracings of vectors opposite the electrical forces were made in three-dimensional display, thus reproducing the actual time sequence of electrical events in those structures. Fixed generators such as the subcortical nuclei were also analyzed with this technique, and multiple generators of N13 potential (N13a and N13b) were visualized. This technique may be useful in the functional evaluation of the somatosensory pathway in the cervical cord.
Successful Fontan-type operation for a nonresectable right ventricular tumor. A large intracavitary right ventricular tumor in a 24-year-old patient was considered nonresectable because it involved the interventricular septum, the free ventricular walls, and the tricuspid valve. Surgical palliation consisted of closure of the tricuspid and pulmonary valves, and the right atrium was anastomosed to the pulmonary artery bifurcation. The patient is asymptomatic 7 years after operation, and the neoplasm (a rhabdomyoma) has not increased in size.
Free radical inhibition and serial chemiluminescence in evolving experimental pancreatitis. Oxygen free radical activity and inhibition were examined in experimental pancreatitis. Twenty-five rats were randomized to five groups: controls received intravenous saline, to simulate pancreatitis one group received intravenous caerulein (5 micrograms kg-1 h-1), and three groups received sodium taurocholate via the pancreatic duct (0.2 ml, 5 per cent), either alone, following allopurinol or immediately before superoxide dismutase. Chemiluminescence (a phenomenon based on the emission of light during chemical reactions and which is dependent on oxygen free radical activity) was used as an index of oxygen free radical activity and was measured in tissue samples at 5-min intervals following induction of pancreatitis. The control mean(s.e.m.) serum amylase level 1 h after induction of pancreatitis was 635(13) units. It was significantly elevated in caerulein-induced pancreatitis, 1833(118) units (P less than 0.05) and exceeded 3000 units in all taurocholate-infused animals. Mean(s.e.m.) chemiluminescence ranged from 44 (8) mV 100 mg-1 at time zero to 404(113) mV 100 mg-1 at 1 h in controls. In caerulein-induced pancreatitis mean(s.e.m.) chemiluminescence peaked at 20 min (1399(239) mV 100 mg-1, P less than 0.02) and in taurocholate-induced pancreatitis at 15 min (2316(95) mV 100 mg-1, P less than 0.004). Superoxide dismutase significantly reduced chemiluminescence and hyperamylasaemia in taurocholate groups. Increasing oxygen free radical activity paralleled evolving pancreatitis. Superoxide dismutase may have a therapeutic role in pancreatitis.
Hyperhomocysteinemia: an independent risk factor for vascular disease. BACKGROUND. Hyperhomocysteinemia arising from impaired methionine metabolism, probably usually due to a deficiency of cystathionine beta-synthase, is associated with premature cerebral, peripheral, and possibly coronary vascular disease. Both the strength of this association and its independence of other risk factors for cardiovascular disease are uncertain. We studied the extent to which the association could be explained by heterozygous cystathionine beta-synthase deficiency. METHODS. We first established a diagnostic criterion for hyperhomocysteinemia by comparing peak serum levels of homocysteine after a standard methionine-loading test in 25 obligate heterozygotes with respect to cystathionine beta-synthase deficiency (whose children were known to be homozygous for homocystinuria due to this enzyme defect) with the levels in 27 unrelated age- and sex-matched normal subjects. A level of 24.0 mumol per liter or more was 92 percent sensitive and 100 percent specific in distinguishing the two groups. The peak serum homocysteine levels in these normal subjects were then compared with those in 123 patients whose vascular disease had been diagnosed before they were 55 years of age. RESULTS. Hyperhomocysteinemia was detected in 16 of 38 patients with cerebrovascular disease (42 percent), 7 of 25 with peripheral vascular disease (28 percent), and 18 of 60 with coronary vascular disease (30 percent), but in none of the 27 normal subjects. After adjustment for the effects of conventional risk factors, the lower 95 percent confidence limit for the odds ratio for vascular disease among the patients with hyperhomocysteinemia, as compared with the normal subjects, was 3.2. The geometric-mean peak serum homocysteine level was 1.33 times higher in the patients with vascular disease than in the normal subjects (P = 0.002). The presence of cystathionine beta-synthase deficiency was confirmed in 18 of 23 patients with vascular disease who had hyperhomocysteinemia. CONCLUSIONS. Hyperhomocysteinemia is an independent risk factor for vascular disease, including coronary disease, and in most instances is probably due to cystathionine beta-synthase deficiency.
The post-occlusive hyperemic response in patients with systemic sclerosis. We investigated post-ischemic hyperreactive cutaneous blood flow in patients with primary Raynaud's phenomenon and Raynaud's phenomenon secondary to systemic sclerosis (SSc). Reactive hyperemia was measured over a locally warmed area of skin, using a laser Doppler flowmeter, following 5 minutes of suprasystolic occlusion of blood flow. We found that patients with primary Raynaud's phenomenon had normal post-ischemic blood flow compared with normal controls. In contrast, patients with SSc had reduced levels of baseline and peak blood flow compared with either the primary Raynaud's phenomenon patients or the normal subjects. Infusion of carbaprostacyclin, a potent prostacyclin analog vasodilator, did not increase blood flow in the SSc patients, nor did it restore the reactive hyperemic response. These findings are consistent with the hypothesis that patients with the nonvasoconstricted condition of SSc have fixed structural defects that limit cutaneous microvascular blood flow.
Trends in thirty years of vaginal hysterectomy. Vaginal hysterectomy, as currently performed at the University of Vienna, was first described by Halban in 1932. From 1955 to 1985, a total of 9,967 hysterectomies were performed. The vaginal route was used for 6,078 (60.9 per cent) of these procedures. Sixty-four per cent of the women operated upon were multiparous, 27 per cent were uniparous and 8 per cent were nulliparous. A comparison of the periods 1955 to 1975 and 1976 to 1985 revealed the following trends: the incidence of uterine myomas (30.6 to 27.1 per cent), in situ carcinoma of the cervix (6.5 to 7.9 per cent) and endometrial carcinoma (1.4 to 0.6 per cent) remained largely constant. In the past decade, indications for positional abnormalities (uterine descent and prolapse) were encountered more often (27.6 to 41.6 per cent) than in the first observation period, while the incidence of recurrent metrorrhagia was found to decline (33.9 to 22.8 per cent). The most common complications included hemorrhage during the operation, lesions of the bladder, hemorrhage until 48 hours after surgical treatment and hemorrhage from days 2 to 14 postoperatively (around 0.5 per cent, respectively). During the second observation period, no postoperative fistulas developed. Two instances of tubal prolapse were seen. Laparotomy was done in four of 6,078 instances. Two patients died of septic complications. Whenever possible, we prefer vaginal hysterectomy because of its low complication rate, low mortality rate and low postoperative morbidity.
Comparison of the Goode T-tube with the Armstrong tube in children with chronic otitis media with effusion. Treatment of otitis media with effusion is focused on reaeration of the middle ear cavity. In achieving long-term aeration, the insertion of ventilation tubes that have a long duration of stay can be beneficial. The results are presented of a trial in which the Goode T-tube was compared with the Armstrong tube. Fifteen children were treated between 1981 and 1986 with a T-tube in one ear and a conventional tube in the other. The results are different with regard to duration of stay in the tympanic membrane. Re-insertions were necessary in 47 per cent in the Armstrong group and in 20 per cent in the T-tube group. Otorrhoea occurred in 20 per cent of the Armstrong and 13 per cent of the T-tube intubated ears. A persistent perforation was present in 6 per cent of the ears in both groups. It is concluded that the Goode T-tube is indicated primarily in cases when long-term ventilation is needed.
Effects of heparin versus saline solution on intermittent infusion device irrigation. The purpose of this study was to compare the effectiveness of 1 ml of 0.9% sodium chloride with 10 units of heparin in 1 ml sodium chloride solution, both containing benzyl alcohol, in maintaining patency and reducing the incidence of phlebitis in patients with intermittent infusion devices. The subjects (N = 32) were randomly assigned in a double-blind experimental design. Repeated-measures analysis of variance revealed no significant difference between the groups in phlebitis or patency variables. The results from this controlled study would suggest that 0.9% sodium chloride is as effective as 10 units of heparin in sodium chloride solution in maintaining intermittent infusion device patency and preventing phlebitis.
Moustache appearance in craniopharyngiomas: unique magnetic resonance imaging and computed tomographic findings of perifocal edema. This report describes two cases of craniopharyngioma with perifocal edema. In both patients, computed tomography and magnetic resonance imaging (MRI) revealed that the tumors occupied the suprasellar cistern, invaginated the floor of the 3rd ventricle and were tightly adherent to the ventricular walls. The intraventricular portions of the tumors were cystic, containing protein-rich fluid as suggested by MRI and confirmed by operative findings. There was perifocal edema in the hypothalamus adjacent to the intraventricular tumor, the optic tracts, and the posterior limbs of the internal capsules, resembling the shape of a moustache on axial computed tomographic and MRI scans. The perifocal edema subsided after treatment of the intraventricular tumor by surgical resection or radiation therapy. The "moustache" appearance seems a unique, characteristic feature of perifocal edema, which is observed infrequently with certain craniopharyngiomas.
Osler-Weber-Rendu disease and pulmonary arteriovenous fistulas. Deterioration and embolotherapy during pregnancy. Several reports have implicated pregnancy as a cause of deterioration in patients with pulmonary arteriovenous fistulas. We report a 27-year-old woman with multiple pulmonary arteriovenous fistulas who required coil spring embolotherapy in her 24th week of pregnancy due to a spontaneous hemothorax and hypoxemia.
Surgical approach to the retrocrural lymph nodes. Removal of retrocrural lymph nodes requires an approach other than the infradiaphragmatic retroperitoneal access generally used in the surgical management of testicular tumours. The transperitoneal route given access, at best, to the origin of the superior mesenteric artery, but advanced testicular tumours occasionally require retrocrural node dissection. We describe a useful surgical approach to these nodes and the underlying anatomy.
Prenatal diagnosis of fetal intracranial calcifications. A case is presented wherein fetal intracranial calcifications as a result of intrauterine cytomegalovirus infection were visualized by computed tomography and magnetic resonance imaging at 36 weeks' gestation. Diagnosis of in utero cytomegalovirus infection was made by isolation of the virus from amniotic fluid. No symptomatic abnormality has been noted in the neonatal period except periventricular calcifications.
Primary lymphoma of bone: a clinicopathologic study of 25 cases reported over 10 years. Twenty-five cases of primary lymphoma of bone (PLB) reported over a 10-year period were reviewed. The presenting symptom was related to involvement of a single bone with or without regional nodal disease. None showed dissemination of lymphoma in the subsequent six months. Patients affected were 7-65 years of age. An equal predilection for the axial and appendicular skeleton was noted. Histologically, the commonest subtype was diffuse histiocytic lymphoma (DHL, 17 cases), whereas four were poorly differentiated lymphocytic (PDL) type and another four were unclassifiable. Follow-up was available in 18 out of 25 patients for periods ranging from 7 months to 8 years. On clinicopathologic correlation we found that 75% of disease-free patients had a DHL whereas 60% of those alive with disease had a PDL. This study reiterates the view that PLB has a good prognosis and the DHL subtype is especially amenable to complete eradication.
Oral contraceptives and breast cancer. Among women in general the risk of breast cancer through 59 years of age does not appear to be affected appreciably by the use of oral contraceptives. Nonetheless, concern continues to be expressed about the effects of early age at first use, long-term duration of use, formulation, and a variety of other factors thought to influence breast cancer risk in the presence of oral contraception. A number of recent studies restricted to young women suggest that long-term use may increase the risk of disease occurring very early, but the present lack of consistent findings in well-conducted epidemiologic studies prevents any certain conclusion with regard to cause-and-effect. However, if an increased risk were indeed present, the most plausible interpretation is that long-term oral contraception promotes earlier clinical manifestation of breast cancer in some women while having no net impact on their lifetime risk of the disease.
Adjuvant therapy for node-negative breast cancer. The use of prognostic factors in selecting patients. Patients with invasive breast cancer and pathologically negative lymph nodes (NO) have a favorable 10-year survival rate, particularly with small (less than 1 cm) primary tumors. Overall, however, 20% to 35% will experience recurrence with local therapy only. Adjuvant chemotherapy or tamoxifen have prolonged disease-free survival (DFS), but not overall survival (OS). Unanswered questions of optimal end point (DFS or OS) and the risk of treating many to benefit few have prompted clinicians to use prognostic indicators to facilitate treatment recommendations. Currently, the most readily available and accurate information comes from TNM staging, pathologic features, and hormone receptors. Ploidy, S-phase fraction, HER-2-neu amplification or over-expression, and cathepsin-D may be useful prognostic indices. Until a more precise system of weighing several prognostic variables is developed, the decision to recommend adjuvant systemic therapy in this generally good prognosis group will have to be thoughtfully considered by patient and physician. Whenever possible, patients should be encouraged to enter clinical trials.
Primary Ewing sarcoma: follow-up with Ga-67 scintigraphy. While avid accumulation of gallium-67 citrate and technetium-99m methylene diphosphonate (MDP) occurs initially in most cases of primary Ewing sarcoma, uptake after therapy is less well defined. Thirty patients with Ewing sarcoma who underwent Ga-67 and bone scintigraphy at diagnosis, at completion of therapy, and at relapse from 1978 to 1988 were evaluated. All 30 patients showed less primary site Ga-67 activity following therapy. Twenty-three of 28 patients who underwent corresponding bone scintigraphy showed less uptake, but residual activity was usually more intense than with Ga-67. Avid reaccumulation of Ga-67 occurred in four of five patients with primary site relapse, while patients who underwent bone scintigraphy showed less change. It was concluded that a greater decrease in Ga-67 than in Tc-99m MDP uptake often occurs in patients successfully treated for primary Ewing sarcoma. Information obtained at Ga-67 scintigraphy is most likely to be helpful if results of bone scintigraphy remain abnormal or if occult relapse is suspected.
The evaluation of the abdominal aorta: a "how-to" for cardiac sonographers. A thorough evaluation of the abdominal aorta can be readily achieved by use of the standard views of the echocardiographic examination. The ultrasound evaluation of the abdominal aorta represents a logical extension of the standard echocardiographic examination of the adult patient. This article provides the information needed to carry out a complete ultrasound examination of the abdominal aorta including the anatomy, the vascular disease, and the steps involved in accomplishing the ultrasound examination of the abdominal aorta.