123rc/medical_text huggingface dataset:
Principles of treatment of pediatric solid tumors. Great strides have been made in the treatment of pediatric solid tumors over the last three decades. A multimodality approach involving a combination of surgery, radiation therapy, and chemotherapy is now used in the treatment of these diseases. This article reviews the principles that guide the use of these modalities and the multidisciplinary approach used to integrate them into a coordinated treatment plan. The role of each modality in the control of local and systemic disease is described. Radiation treatment planning, dose fractionation, and toxicity are also discussed.
Hypoxia induces a specific set of stress proteins in cultured endothelial cells. Vascular endothelial cells (EC) are the initial cells within the vascular wall exposed to decreases in blood ambient oxygen concentration. The mechanisms by which they tolerate low levels of oxygen are unknown, but may parallel the response to other cellular stresses, such as heat shock. After 4-8 h of hypoxia, we found a decrease in total protein synthesis in both cultured bovine aortic and pulmonary arterial EC. SDS-PAGE and autoradiographic analysis of [35S]methionine-labeled proteins demonstrated the concomitant induction of a specific set of proteins (Mr 34, 36, 47, and 56 kD) in both cell types. These hypoxia-associated proteins (HAPs) were cell-associated and up-regulated in a time- and oxygen concentration-dependent manner. Comparison of these proteins with heat shock proteins (HSPs) demonstrated that HAPs were distinct from HSPs. EC maintained chronically in 3% O2 continued to synthesize elevated levels of HAPs, yet further up-regulated these proteins when exposed to 0% O2. The presence of five times the normal media glucose concentration did not alter the appearance of HAPs. Hypoxia sensitive renal tubular epithelial cells up-regulated no proteins corresponding to HAPs and were irreversibly damaged within 8 h of exposure to 0% O2. In vitro translation experiments demonstrated that the steady-state level of several mRNAs was higher in the anoxic EC than in normoxic EC and encoded for proteins of Mr 32, 35, 37, 40, and 48 kD that were different from proteins encoded by HSP mRNAs. The induction of HAPs during acute hypoxia and their continued synthesis in chronic hypoxia suggest that HAPs may be important in the maintenance of endothelial cell integrity under conditions of decreased ambient oxygen.
The frequency, causes and timing of death within 30 days of a first stroke: the Oxfordshire Community Stroke Project. In a prospective, community-based study of 675 consecutive patients with a first-ever stroke, of whom over 90% had computed tomography (CT) and/or necropsy examinations, 129 deaths occurred within 30 days of the onset of symptoms, a case fatality rate (CFR) of 19%. The 30 day CFR for patients with cerebral infarction was 10% (57 of 545, for primary intracerebral haemorrhage 52% (34 of 66), for subarachnoid haemorrhage 45% (15 of 33) and for those of uncertain pathological type 74% (23 of 31). The CFR for patients who had been functionally dependent pre-stroke was 33% compared with 17% for those who had been independent pre-stroke. The age-adjusted relative risk of death for patients who had been functionally dependent pre-stroke was not significantly greater (1.8, 95% confidence interval 0 to 4.3). There was a significant trend for CFR to increase with age (Chi square for trend = 4.0, p less than 0.05). This relationship was found in those patients who had been functionally independent prestroke (Chi square for trend = 7.9, p less than 0.005) but not in those who had been dependent pre-stroke (Chi square for trend = 0.5, NS). The pattern of increasing CFR with increasing age amongst those who had been independent prestroke was seen particularly in patients with cerebral infarction (Chi square for trend = 8.6, p less than 0.005). The age-adjusted relative risk of death for patients with cerebral infarction who had been functionally dependent pre-stroke was 2.2 (95% confidence interval 1.2 to 4.1). Fifty three percent of all deaths within 30 days of stroke were due to the direct neurological sequelae of the stroke.
Epidermal growth factor receptor expression in normal ovarian epithelium and ovarian cancer. I. Correlation of receptor expression with prognostic factors in patients with ovarian cancer. Previous studies in breast and bladder cancer have suggested that epidermal growth factor receptor is expressed by only a proportion of cancers and is associated with poor clinical outcome. We used a monoclonal antibody specifically reactive with the extracellular domain of the epidermal growth factor receptor to localize this receptor immunohistochemically in frozen sections of normal ovary and epithelial ovarian cancer. Normal ovarian epithelium was found to express epidermal growth factor receptor in all cases. Among 87 ovarian cancers, however, 23% did not express immunohistochemically detectable receptor. Epidermal growth factor receptor expression was not related to histologic grade or stage, but was associated with poor survival (p less than 0.05). The median length of survival of patients with tumors that did not express epidermal growth factor receptor was 40 months compared with 26 months in patients with tumors that did express epidermal growth factor receptor. As in breast and bladder cancer, expression of epidermal growth factor receptor in ovarian cancer appears to be a poor prognostic factor.
Intraoperative blood pressure. What patterns identify patients at risk for postoperative complications? While monitoring blood pressure is a routine part of intraoperative management, several methods have been proposed to characterize intraoperative hemodynamic patterns as predictors of postoperative complications. In this prospective study of a high-risk population of hypertensive and diabetic patients undergoing elective noncardiac surgery, one objective was to compare different approaches to the assessment of intraoperative hemodynamic patterns to identify those patterns most likely to be associated with postoperative complications. Twenty-one per cent of the 254 patients sustained cardiac or renal complications after operation. Patients with more than 1 hour of greater than or equal to 20-mmHg decreases in mean arterial pressure (MAP) or patients with less than 1 hour of greater than or equal to 20-mmHg decreases and more than 15 minutes of greater than or equal to 20-mmHg increases were at highest risk for postoperative complications. Together these two patterns had a 46% sensitivity rate and a 70% specificity rate in predicting postoperative complications. Using 20% change in intraoperative MAP produced results nearly identical to 20-mmHg changes. When the duration of 20-mmHg changes was accounted for, changes of a greater magnitude (e.g., 40 mmHg) were not significant independent predictors of complications. The use of the mean difference from preoperative MAP was misleading because patients who experienced both high and low MAPs tended to have nearly normal mean MAPs, but high complication rates. The absolute magnitude of intraoperative MAPs, regardless of the preoperative levels, also was evaluated. The overall mean intraoperative MAP was not a significant predictor of complications. Specific intraoperative MAPs (e.g., less than 70 mmHg and more than 120 mmHg) also were evaluated. While neither was a significant predictor, there was a trend for increased complications among patients whose MAPs decreased to less than 70 mmHg. Intraoperative blood pressure should be analyzed in relation to the patient's preoperative blood pressure. Prolonged changes of more than 20 mmHg or 20% in relation to preoperative levels were significantly related to complications.
Timing and topography of cerebral blood flow, aura, and headache during migraine attacks. Ten years of study has resulted in considerable but fragmented knowledge about regional cerebral blood flow in migraine with aura (classic migraine). In the present study, the number of repeatedly studied patients (n = 63) was large enough to determine statistically significant sequences of events and statistically significant spatial relations. The first observable event was a decrease of regional cerebral blood flow posteriorly in one cerebral hemisphere. Further development of this pathological process was accompanied by the aura symptoms. Thereafter headache occurred while regional cerebral blood flow remained decreased. During the headache phase, regional cerebral blood flow gradually changed from abnormally low to abnormally high without apparent change in headache. In some patients headache disappeared while regional cerebral blood flow remained increased. Although regional cerebral blood flow reduction and aura symptoms in the great majority of patients were unilateral, one-third had bilateral headache. Unilateral headache usually localized to the side on which regional cerebral blood flow was reduced and from which the aura symptoms originated (i.e., aura symptoms were perceived to occur contralaterally but presumably originated in the hypoperfused hemisphere). Our results suggest a simple model for migraine attacks: A pathological disturbance in one cerebral hemisphere causes the aura symptoms and after a time delay, it also causes the headache by stimulating local vascular nociceptors. Bilateral headache caused by a unilateral cerebral disturbance may be explained by recent neuroanatomical and neurophysiological findings.
Reduced platelet aggregability and thromboxane release after rebleeding in patients with subarachnoid hemorrhage. Serial blood samples were obtained from 80 patients with subarachnoid hemorrhage (SAH) to study adenosine diphosphate-induced platelet aggregation and associated thromboxane B2 release. The goal of the investigation was to detect whether reduced platelet function is involved in rebleeds. Seventeen patients (21%) suffered a rebleed, six of those experiencing their first rebleed within 24 hours after SAH. Therefore, most platelet function studies were performed after rebleeds. Thromboxane release was lower in patients with rebleeds than in the others, both before and after rebleeding, although statistical significance was reached only in samples collected after rebleeds. Patients rebleeding within 24 hours after SAH had lower platelet aggregability (p = 0.037) than patients without a rebleed in the samples taken within 3 days after SAH. The results suggest that reduced platelet aggregability and thromboxane release are involved in rebleeds following primary SAH.
Comparison of STIR and spin-echo MR imaging at 1.5 T in 45 suspected extremity tumors: lesion conspicuity and extent. Short inversion time inversion recovery (STIR) imaging and a double-echo spin-echo (SE) sequence at 1.5 T in 45 sequential patients with suspected extremity tumors were compared to assess the number of lesions detected, subjective conspicuity of lesions, approximate volume of abnormality detected in each lesion, and identification of peritumoral brightening in tissues adjacent to each lesion. STIR sequences enabled detection of all 45 lesions; 44 were detected with the SE sequence. Tumor appeared most conspicuous on STIR images in 35 patients (78%) and was most conspicuous on SE images in 10 patients (22%). Peritumoral brightening, which indicated either peritumoral edema or microscopic tumor infiltration, was detected in 20 patients but was detected only with STIR sequences in nine patients. It is concluded that, although STIR and SE sequences are comparable for lesion detection in the extremities, most lesions appear more conspicuous with STIR. STIR may enable detection of a greater volume of abnormality than SE sequences and may therefore have important implications for local staging and surgical and radiation therapy planning.
From Leningrad to the day-care center. The ubiquitous Giardia lamblia. Giardiasis is recognized as a worldwide public health problem. Seroprevalence data from both the developing and developed world show high rates of carriage in populations at risk for fecal-oral transmission, such as children in day-care centers. Outbreak investigation has expanded our understanding of reservoirs for Giardia lamblia and of the routes of transmission. Various host factors have been associated with infection. The pathogenesis of giardial infections is being elucidated, in particular the role of lectin activation in producing disease. Three standard chemotherapeutic agents are available in the United States. The institution of community-wide prevention measures is equally important. Current areas of investigation including antigenic composition and enzymatic variants should result in effective forms of immunotherapy, while more effective forms of chemoprophylaxis could assist in eradicating the pathogen from institutional settings.
Sleep disturbances in HIV-infected homosexual men. To provide a better understanding of the etiology of subjective sleep complaints in HIV-infected individuals, a study to evaluate sleep/wake disturbances in 10 healthy HIV-infected male volunteers was performed. All subjects were HIV-infected but had no history of AIDS-related infections, and considered clinically asymptomatic. Interviews and sleep questionnaires revealed sleep complaints in nine subjects. Five healthy HIV-seronegative male subjects, with no history of sleep complaints, were also evaluated. Sleep architecture analyses detected that, in comparison to published normative data and to negative controls, there was a significant increase in the total percentage of slow wave sleep (SWS) and an increase in the percentage of SWS in the later sleep cycles. When compared with normative data, an increase in stage 1 shifts, rapid eye movement (REM) periods, and arousals were also observed in the HIV-infected group. Significant decreases in sleep latency, total percentage stage 2 sleep, and average REM durations were also observed in the HIV-infected group compared with normative data. These sleep architecture abnormalities could not be attributed to known sole primary sleep disorders, first night effect, medications, anxiety or depression. This study indicates that sleep disturbances occur early in the course of HIV infection and suggests that the observed alterations of sleep physiology may be a consequence of central nervous system involvement and/or immune defense mobilization in the early phases of HIV infection.
Posttraumatic torticollis. We report six cases of torticollis precipitated by neck trauma. The dystonia began 1 to 4 days after the trauma and differed clinically from idiopathic torticollis by marked limitation of range of motion, lack of improvement after sleep ("honeymoon period"), and absence of geste antagonistique. Worsening with action was not present; nor was there improvement with support as seen with idiopathic torticollis. Onset of pain immediately after the trauma and marked spasms of the paracervical muscles were other predominant features. Anticholinergic therapy was without benefit; however, some improvement occurred with botulinum toxin injection. It is concluded that torticollis can be caused by peripheral trauma and that it has unique clinical characteristics.
Exercise intolerance in patients with heart failure and preserved left ventricular systolic function: failure of the Frank-Starling mechanism Invasive cardiopulmonary exercise testing was performed in 7 patients who presented with congestive heart failure, normal left ventricular ejection fraction and no significant coronary or valvular heart disease and in 10 age-matched normal subjects. Compared with the normal subjects, patients demonstrates severe exercise intolerance with a 48% reduction in peak oxygen consumption (11.6 +/- 4.0 versus 22.7 +/- 6.1 ml/kg per min; p less than 0.001), primarily due to a 41% reduction in peak cardiac index (4.2 +/- 1.4 versus 7.1 +/- 1.1 liters/min per m2; p less than 0.001). In patients compared with normal subjects, peak left ventricular stroke volume index (34 +/- 9 versus 46 +/- 7 ml/min per m2; p less than 0.01) and end-diastolic volume index (56 +/- 14 versus 68 +/- 12 ml/min per m2; p less than 0.08) were reduced, whereas peak ejection fraction and end-systolic volume index were not different. In patients, the change in end-diastolic volume index during exercise correlated strongly with the change in stroke volume index (r = 0.97; p less than 0.0001) and cardiac index (r = 0.80; p less than 0.03). Pulmonary wedge pressure was markedly increased at peak exercise in patients compared with normal subjects (25.7 +/- 9.1 versus 7.1 +/- 4.4 mm Hg; p less than 0.0001). Patients demonstrated a shift of the left ventricular end-diastolic pressure-volume relation upward and to the left at rest. Increases in left ventricular filling pressure during exercise were not accompanied by increases in end-diastolic volume, indicating a limitation to left ventricular filling.
Papillary cystic neoplasm of the pancreas: radiological and pathological characteristics in 11 cases. Clinical charts, radiological features, macroscopic and microscopic findings, and clinical follow-up data were retrospectively reviewed in 11 patients with papillary cystic neoplasm of the pancreas (PCNP). The patients were nine women and two men, aged from 13 to 51 years with a mean age of 25 years. The greatest diameter of the PCNPs ranged from 2.5 cm to 14.0 cm with a mean size of 7.5 cm. Six tumours were located in the tail of the pancreas, two in the body and three in the head. Most patients complained of abdominal pain or a mass. Ultrasonographic and/or computed tomography findings showed five solid, four mixed (solid and cystic) and two cystic types of tumour. Angiographically, PCNP was either a hypovascular or mild hypervascular mass with a displacement of the surrounding vessels. No vascular encasement was seen. Macroscopically all 11 tumours consisted of a well defined solid mass with degenerative change of various widths, including haemorrhage, necrosis or dystrophic calcification, and were represented by three radiological types of PCNP. The 11 patients with PCNP survived for from 3 to 253 months after curative resection without any signs of local recurrence or remote metastasis. PCNP usually affects the distal portion of the pancreas of young women. Despite its huge size, PCNP should be explored with aggressive surgical intent because of the inherently good prognosis.
The relationship of intraluminal shunting to technical results after carotid endarterectomy. This study evaluates the incidence of defects on the intraoperative angiograms of 160 carotid endarterectomies performed in 146 patients, 81 of 160 (50.6%) with a shunt and 79 of 160 operations (49.4%) performed without a shunt. Angiographic defects were identified in 34 of 160 carotid endarterectomies (21%), of which 21 of 34 (65%) resulted in a greater than 20% stenosis of the internal carotid artery (ICA). There were defects in 6 of 81 (7.4%) shunted vessels compared to 16 of 79 (20%) of those not shunted (p less than 0.05). Thirty-one vessels were reexplored 11 of 81 (13.5%) of those shunted and 20 of 79 (20%) of those not shunted (p less than 0.05). There were four strokes (2.5%) (2 in each group) and one death due to myocardial infarction (0.6%) in the postoperative period. Duplex follow-up from 1-60 months (median 22 months) was available in 114 of 160 (71%) endarterectomies. A stenosis of greater than 50% was detected in 7 of 114 (6%) carotid arteries; 5 of the 7 (71%) were shunted and 2 (29%) were nonshunted. Unrepaired defects were present in 3 of 7 (43%) and no defects in the remaining 4 of 7 (57%) arteries. We conclude that the use of a shunt significantly decreases the number of ICA defects detected angiographically and that immediate revision of demonstrable defects can be undertaken with low morbidity and does not predispose the patient to recurrent stenosis.
Haemophilus influenzae meningitis with prolonged hospital course. A retrospective evaluation of Haemophilus influenzae type b meningitis observed over a 2-year period documented 86 cases. Eight of these patients demonstrated an unusual clinical course characterized by persistent fever (duration: greater than 10 days), cerebrospinal fluid pleocytosis, profound meningeal enhancement on computed tomography, significant morbidity, and a prolonged hospital course. The mean age of these 8 patients was 6 months, in contrast to a mean age of 14 months for the entire group. Two patients had clinical evidence of relapse. Four of the 8 patients tested for latex particle agglutination in the cerebrospinal fluid remained positive after 10 days. All patients received antimicrobial therapy until they were afebrile for a minimum of 5 days. Subsequent neurologic examination revealed a persistent seizure disorder in 5 patients (62.5%), moderate-to-profound hearing loss in 2 (25%), mild ataxia in 1 (12.5%), and developmental delay with hydrocephalus which required shunting in 1 (12.5%). One patient had no sequelae.
Erythropoietin response to anemia as a function of age. The erythropoietin (EPO) response to anemia was assessed for 244 subjects aged 1-64 years (mean 45.2 years) and 121 subjects aged 65-94 years (mean 68.3 years). Subjects included non-anemic individuals as well as those with anemia of various etiologies, excluding renal disease and pregnancy. Significant inverse correlations between serum immunoreactive EPO and hematocrit were noted for both groups. Regression lines failed to show a significantly lower slope or y-intercept for older compared to younger subjects. EPO levels were not significantly lower for older compared to younger subjects when controlled for hematocrit level. These results suggest that the EPO response to anemia in older subjects is similar to that of younger subjects.
Clinical presentation, treatment, and outcome of trilateral retinoblastoma. In this report, three new cases of trilateral retinoblastoma are presented. The clinical presentation, treatment, and outcome of the patients are described and compared with those of 32 cases that have been previously reported in the literature. A positive family history was obtained in 68% of the patients. The mean age at diagnosis of bilateral retinoblastoma was 7.2 months. The mean age at diagnosis of trilateral disease was 39.7 months, resulting in a mean latent interval of 32.6 months. The mean time from diagnosis of trilateral retinoblastoma to death was 6.6 months, and all patients died with spinal metastases. The patients who received no therapy survived an average of 1.3 months after the diagnosis of trilateral disease. The patients who received any form of definitive therapy survived 9.7 months. Five patients who had complete or dramatic response to therapy by computed tomography scans had local intracranial tumor present at autopsy. Therefore, more aggressive local therapy may be warranted.
Surgical treatment of aneurysm or dissection involving the ascending aorta and aortic arch, utilizing circulatory arrest and retrograde cerebral perfusion. Recently we replaced the ascending aorta and aortic arch in 8 patients with aneurysm or dissection, using profound hypothermic circulatory arrest with retrograde cerebral perfusion. There were no operative deaths. Open aortic anastomosis facilitated repair of the aortic arch without clamping the arch tributaries, and embolism due to particulate debris from clamping of the arch vessels was eliminated. Retrograde cerebral perfusion during profound hypothermic circulatory arrest is a simplified technique that may protect the brain. This method offers advantages over previously described methods, particularly in obviating dissection of the arch tributaries and the clamping thereof, and in protecting the central nervous system.