123rc/medical_text huggingface dataset:
Sphincter preservation in rectal cancer by local excision and postoperative radiation therapy. The authors report the preliminary results of 14 patients with localized, mobile, resectable rectal cancer treated with local excision and postoperative radiation therapy (RT). All had negative surgical resection margins and two received 5-fluorouracil (5-FU). The median follow-up was 29 months (4-43 months). The 3-year actuarial survival was 88%. The incidence of local failure was 7% (only site of failure) and 21% (component of failure). The incidence of local failure increased with T stage (T1, 0/3 [0%]; T2, 1/7 [14%]; and T3, 2/4 [50%]) and tumor size (greater than 3 cm, 33%, versus less than or equal to 3 cm, 0%). Three patients developed local failure at 6, 15, and 21 months. Three underwent a salvage abdominoperineal resection and were locally controlled at 2 and 28 months following salvage surgery. One patient underwent an abdominoperineal resection for a clinically presumed local failure; however, no tumor was found in the specimen. Therefore, the 13 patients who either were initially locally controlled or underwent salvage or nonsalvage surgery had no evidence of disease in the pelvis at the time of last follow-up. Local excision and postoperative RT may be an alternative to standard surgery in selected cases. However, additional follow-up and more experience are needed in order to determine if this approach will ultimately have local control and survival rates similar to those of a low anterior resection or an abdominoperineal resection.
One-stage laryngotracheoplasty. This article documents the evolution of our approach to the repair of subglottic stenosis in infants. With increasing experience in the management of subglottic stenosis using the anterior cricoid split procedure, we extended our procedure to include older children. This then led to the use of the one-stage procedure for repair of severe and mature subglottic stenosis. We present the results of surgical repair in 13 patients. Extubation was accomplished in 12 of 13 patients using one-stage laryngotracheoplasty.
Results of transsphenoidal extirpation of craniopharyngiomas and Rathke's cysts. Fourteen patients undergoing transsphenoidal extirpation of craniopharyngiomas or Rathke's cysts underwent endocrinological evaluation before and after surgery. One patient died during the procedure because of uncontrollable arterial bleeding. The other patients were followed for up to 16 years (average, 8.5 years). One patient had recurrence of tumor 12 years after surgery. Another patient, the only one operated on because of a recurrent craniopharyngioma after previous radiation therapy, died 2 years after the transsphenoidal operation. No patient recovered pituitary functions that had been lost before surgery. One patient, who had an isolated growth hormone deficiency, and another, who had panhypopituitarism with sustained antidiuretic hormone secretion, had no change postoperatively from their preoperative endocrine status. The other 11 patients lost pituitary function and required pharmacological replacement of one to four pituitary hormones.
Breast cancer: the military's experience at Wilford Hall USAF Medical Center. We reviewed the experience with breast cancer at Wilford Hall USAF Medical Center for the years 1978 through 1988. A total of 868 cases were identified in the Wilford Hall Tumor Registry; overall 5-year and 10-year survivals were 63% and 39%, respectively. Infiltrating ductal carcinoma represented the principal histologic category. The other predominant variants included invasive lobular carcinoma, lobular carcinoma in situ, and ductal carcinoma in situ. Until recently, most of these patients (90%) had modified radical mastectomy as their definitive surgical therapy, with chemotherapy reserved primarily for patients with advanced disease.
Multiplexing studies of effects of rapid atrial pacing on the area of slow conduction during atrial flutter in canine pericarditis model. BACKGROUND. We report that rapid atrial pacing interrupts atrial flutter when the orthodromic wave front from the pacing impulse is blocked in an area of slow conduction in the reentry circuit. To characterize the area of slow conduction during atrial flutter and rapid pacing, we studied 11 episodes of induced atrial flutter, mean cycle length 157 +/- 20 msec, in eight dogs with sterile pericarditis. METHODS AND RESULTS. Atrial electrograms were recorded simultaneously from 95 pairs of right atrial electrodes during the interruption of atrial flutter by rapid atrial pacing, mean cycle length 139 +/- 21 msec. Areas of slow conduction during atrial flutter were demonstrated at one to three sites in the reentry circuit. After rapid pacing captured the reentry circuit, one area of slow conduction either disappeared (10 episodes) or the degree of slow conduction in an area of slow conduction decreased (one episode). Both changes were in association with activation of the region by a wave front from the pacing impulse that arrived from a direction different than that during the induced atrial flutter. Interruption of atrial flutter during rapid pacing occurred when the orthodromic wave front from the pacing impulse blocked in an area of slow conduction that had either newly evolved during rapid pacing (seven episodes) or that was previously present (four episodes). CONCLUSIONS. Areas of slow conduction present during atrial flutter and rapid pacing of atrial flutter are functional and depend on both the atrial rate and the direction of the circulating wave fronts. Interruption of atrial flutter by rapid pacing results from block of the orthodromic wave front of the pacing impulse in an area of slow conduction in the reentry circuit.
Reduced atrial contribution to left ventricular filling in patients with severe tricuspid regurgitation after tricuspid valvulectomy: a Doppler echocardiographic study. Patients undergoing valvulectomy for isolated tricuspid valve endocarditis offer the unique opportunity to study the effects of acquired right ventricular volume overload on left ventricular filling in persons free of pulmonary hypertension and preexisting left heart disease. Eleven patients who had undergone total or partial removal of the tricuspid valve were compared with 11 age-matched control subjects; Doppler echocardiographic techniques were used to quantify changes in left ventricular filling and to relate them to changes in left ventricular and left atrial geometry caused by right ventricular and right atrial distension. The late diastolic fractional transmitral flow velocity integral, a measure of the left atrial contribution to left ventricular filling, was significantly decreased in patients undergoing tricuspid valvulectomy compared with control subjects (0.22 +/- 0.11 versus 0.32 +/- 0.09; p less than 0.04). Severe tricuspid regurgitation in these patients resulted in marked right atrial distension, reversal of the normal interatrial septal curvature and compression of the left atrium such that left atrial area was significantly smaller than in control subjects (5.9 +/- 2.2 versus 8.6 +/- 1.2 cm2/m2; p less than 0.005). Acting as a receiving chamber, the left ventricle was maximally compressed by the volume-overloaded right ventricle in late diastole, coincident with the timing of atrial systole, resulting in a significant increase in the left ventricular eccentricity index compared with that in control subjects (1.35 +/- 0.14 versus 1.03 +/- 0.1; p less than 0.001). Thus, right ventricular volume overload due to severe tricuspid regurgitation results in left heart geometric alterations that decrease left atrial preload, impair left ventricular receiving chamber characteristics and reduce the atrial contribution to total left ventricular filling.
Effects of acute alcohol intake on tolerance to hypotension. The specific aim of this research was to test the hypothesis that intoxication with alcohol results in poor tolerance to hemorrhage. This was evaluated on the basis of blood pressure, cardiac output respiratory rate, blood flow to organs, and survival for 4 hr after hemorrhage. Four groups of six swine per group were used (control, intoxicated, hemorrhage, and intoxicated-hemorrhage). The results revealed that blood alcohol concentrations near 0.1% greatly reduced tolerance to hemorrhage. Intoxicated animals subjected to hemorrhage were unable to maintain an adequate cardiac output, blood pressure, or respiratory rate to sustain life. Pigs tolerated higher blood alcohol concentrations, up to 0.35%, when not exposed to hemorrhage. Also, unintoxicated pigs were able to compensate for severe hemorrhage. Only one of the six pigs in the intoxicated-hemorrhage group survived for 4 hr after hemorrhage. In conclusion the body's ability to compensate and recover from hemorrhage was greatly reduced during intoxication. It is logical to assume that the ability to overcome numerous other stressors may also be reduced during intoxication.
Elevated insulin, norepinephrine, and neuropeptide Y in hypertension. To investigate the relationship between insulin and sympathetic activity, plasma norepinephrine, neuropeptide Y, serum glucose and insulin concentrations were measured in ten age-, weight-, and sex-matched normotensive and untreated hypertensive subjects at fasting and 2 h following ingestion of a 75 g oral glucose dose. Hypertensives had higher fasting serum insulin (27 +/- 6 v 12 +/- 2 microU/mL; P = .02) and plasma norepinephrine (356 +/- 38 v 235 +/- 35 pg/mL; P = .03) concentrations than normotensives. Glucose load increased serum insulin (P less than .001) and plasma norepinephrine concentrations (P = .001) in both groups and hypertensives had still higher postglucose insulin (P = .003) and norepinephrine levels (P = .003) than normotensives. Fasting neuropeptide Y was higher in hypertensives than in normotensives (P = .03) and correlated with age in both groups (r = 0.7; r = 0.77). Postglucose serum insulin correlated positively with plasma norepinephrine (r = 0.75; P = .013) in normotensives, but these parameters correlated negatively in hypertensives (r = -0.7; P = .036). We hypothesize that elevated plasma norepinephrine and neuropeptide Y levels reflect an increased level of sympathetic nervous activity in hypertensives, which in turn may be responsible for the abnormal relationship between plasma NE and insulin levels.
An angiographic technique for three-dimensional determination of arterial supply patterns in cadaver soft tissue. A method for arterial tree mapping that can be used in cadaver soft tissue is presented. In situ angiograms and photographs are supplemented with profile angiograms of relatively narrow bands of tissue from the removed specimen. The described method was better suited for mapping the course and supply patterns of a soft-tissue arterial network than either in situ angiograms or dissection. While practical problems were encountered with most of the solutions used for providing radiopacity or structural support to the vessels, pure barium sulfate was found to be suitable because it filled the vascular tree to the capillary level without leakage during excision of the specimen.
Myocardial temperature during cardiac operations: influence on right ventricular function. Maintenance of right heart integrity is frequently neglected during coronary operations. Right ventricular dysfunction sometimes limits the success of the surgical procedure, however. In addition to the use of cardioplegic solutions, myocardial hypothermia during ischemic cardiac arrest seems to be an important factor for guaranteeing right ventricular performance thereafter. This study was designed to measure myocardial temperature in patients with coronary artery disease who have significant stenosis of the right coronary artery in comparison with those who do not have stenosis of the right coronary artery and to evaluate the influence of myocardial temperature on right ventricular hemodynamics after cardiopulmonary bypass. Right ventricular function was assessed by thermodilution technique, which allows measurement of right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume. Right ventricular temperature differed significantly between the two groups, with the lowest value of 15.1 degrees +/- 1.8 degrees C in the group without stenosis of the right coronary artery and a value of 22.2 degrees +/- 2.1 degrees C in the group with stenosis of the right coronary artery. Left ventricular and septal temperatures were without group differences within the investigation period. Right ventricular hemodynamics were impaired only in the group with stenosis of the right coronary artery with a decrease in right ventricular ejection fraction from 44.2% to 34.1% immediately after termination of bypass and an increase in right ventricular end-diastolic volume index (+38%) and right ventricular end-systolic volume index (+70%). Cardiac index decreased only in this group, too (-22.5%). Analysis of covariance revealed a significant correlation only between changes in right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume and the course of right myocardial temperature. It is concluded that right ventricular hypothermia is more difficult to achieve in patients with a diseased right coronary artery. Constant myocardial hypothermia, however, seems to be important in guaranteeing right ventricular function, which easily can be evaluated by the thermodilution technique.
Headache and acquired immunodeficiency syndrome. Because the acquired immunodeficiency syndrome (AIDS) virus is neurotropic, physicians will continue to see a rise in the number of neurologic complications of this syndrome. Much of this increase will be accompanied by headache, not only as a primary symptom of HIV infection or opportunistic disease but also as a result of diagnostic tests and therapeutic efforts. Complete understanding of the ramifications of headache in AIDS will be important in the 1990s as we continue to treat a younger population, usually affected by benign vascular and muscle contraction-type headache.
Effects of antihypertensive therapy on mechanics of cerebral arterioles in rats. The purpose of this study was to examine effects of antihypertensive treatment on structure and mechanics of cerebral arterioles and the incidence of stroke in stroke-prone spontaneously hypertensive rats (SHRSP). Treatment of hypertension was begun at 3 months of age with cilazapril (45 mg/kg/day), an angiotensin converting enzyme (ACE) inhibitor, or with hydralazine (18 mg/kg/day). Cilazapril and hydralazine reduced systolic arterial pressure (from 195 +/- 8 to 125 +/- 5 and 148 +/- 3 mm Hg, respectively [mean +/- SEM]; p less than 0.05). To examine structure and mechanics of cerebral arterioles, we measured pressure (servonull), external diameter, and cross-sectional area of the vessel wall (histologically) in pial arterioles of normotensive Wistar-Kyoto (WKY) rats and SHRSP that were untreated or that were treated for 3 months with cilazapril or with hydralazine. Arterioles were maximally dilated with EDTA. In WKY rats, cilazapril and hydralazine did not alter pial arteriolar pressure, external diameter, or cross-sectional area of the vessel wall. In SHRSP, both cilazapril and hydralazine reduced cross-sectional area of the vessel wall to levels not significantly different from WKY rats (from 1,911 +/- 155 to 1,244 +/- 101 and 1,388 +/- 59 microns 2, respectively, compared with 1,405 +/- 95 microns 2 for untreated WKY rats). Cilazapril was more effective than hydralazine in reducing pial arteriolar pressure (from 110 +/- 6 to 62 +/- 2 mm Hg with cilazapril versus 79 +/- 5 mm Hg for hydralazine compared with 60 +/- 4 mm Hg for untreated WKY rats). Cilazapril, but not hydralazine, attenuated reductions in external diameter of pial arterioles (from 91 +/- 4 to 100 +/- 4 microns for cilazapril versus 91 +/- 3 microns for hydralazine compared with 107 +/- 3 microns for untreated WKY rats).
Quantitation of G0 and G1 phase cells in primary carcinomas. Antibody to M1 subunit of ribonucleotide reductase shows G1 phase restriction point block. Human cancers have an apparent low growth fraction, the bulk of cells presumed to being out of cycle in a G0 quiescent state due to the inability in the past to distinguish G0 from G1 cells. The allosteric M1 subunit of ribonucleotide reductase (M1-RR) is constitutively expressed by cycling cells (i.e., G1, S, G2-M). It is acquired during transition from G0 to G1, lost during exit to G0 and thus distinguishes G0 from G1 cells. To estimate the proportion of G0 and G1 cells in primary human breast (n = 5) and colorectal (n = 12) adenocarcinomas, we used both analytical DNA flow cytometry (ADFC) and immunoperoxidase staining of sections with the monoclonal antibody to M1-RR (MAb M1-RR). ADFC of fresh tumors revealed a low percentage of cells in the S phase (4.0 +/- 3.4%) but immunoperoxidase staining for M1-RR revealed an unexpectedly high proportion of positive cells (52.4 +/- 12.7%) in the G1, S, G2-M phases indicating a high G1 content of primary human tumors. Thus, human cancers are blocked in transition in G1 and are not predominantly in a G0 or quiescent differentiated state. This block was interpreted to mean that human cancers are responding to putative regulatory events at a restriction point in the G1 phase, such as relative growth factor deficiency, density inhibition, antiproliferative cytokines, or gene products. Using flow cytometry for both DNA and M1-RR content we found that human colon cancer cell lines arrest in the G1 but not G0 phase upon serum deprivation or density inhibition. Similarly, human breast cancer cell lines are arrested in G1 but not G0 phase by medroxyprogesterone acetate (MPA) or tamoxifen exposure. These findings match our in situ observations, and support the concept of a restriction point block in primary human tumors.
Elevated serum bromide concentrations following repeated halothane anaesthesia in a child. A 20-month-old child received 25 brief halothane general anaesthetics over a five-week period to allow cranial irradiation treatments for a posterior fossa ependymoma. Personality change during the last week of the treatment protocol raised the question of possible bromide intoxication. Serum bromide concentrations, using a gold chloride assay technique, were monitored at that time, and at four- and six-week intervals thereafter. Serum bromide concentrations demonstrated a four-fold change during this period ranging from peak levels of 2.2 mEq.L-1 (176 micrograms.kg-1) during the fifth week of treatment decreasing to less than 0.5 mEq.L-1 (less than 40 micrograms.ml-1) six weeks following the end of treatments. This demonstrates the possibility for repetitive, short halothane exposures to result in elevations of serum bromide and the potential of bromide intoxication in paediatric neuro-oncology patients.
Prognostic value of reduced heart rate variability after myocardial infarction: clinical evaluation of a new analysis method. The relation between heart rate variability, measured from standard 24 hour electrocardiogram recordings in patients convalescent after a myocardial infarction, and the occurrence of sudden death and spontaneous, symptomatic, sustained ventricular tachycardia were assessed in a consecutive series of 177 patients admitted with acute myocardial infarction and surviving to 7 days. In addition to the analysis of heart rate variability, the occurrence of non-sustained arrhythmias on 24 hour electrocardiographic monitoring, and the results of clinical assessment, signal averaged electrocardiography and ejection fraction were analysed and were related to outcome. During a median of 16 months of follow up (range 10-30 months) there were 17 end point events (11 (6.2%) sudden deaths) and six (3.4%) episodes of sustained ventricular tachycardia. An index of the width of the frequency distribution curve for the duration of individual RR intervals was used to measure heart rate variability. This mean (SD) index was significantly smaller in those with end point events (16.8 (8.0)) than in those without events (29.0 (11.2)). The relative risk of the occurrence of an end point event in those with a heart rate variability index less than 25 was 7.0. Multivariate analysis showed that of all the variables examined a reduced heart rate variability index was the single most powerful predictor of end point events. Measurement of heart rate variability by this simple, automated, operator-independent method provided useful information on the arrhythmic propensity in patients convalescent after myocardial infarction.
Oral labetalol in hypertensive urgencies. The response to incremental doses of oral labetalol in 16 patients with hypertensive urgencies is presented. After inadequate blood pressure control with 20 mg of intravenous furosemide, each patient received a 300 mg oral dose of labetalol. Subsequent oral doses of labetalol, 100 mg, were administered at 2-hour intervals, if the diastolic blood pressure remained greater than 100 mm Hg. The maximum dose of labetalol per patient was 500 mg. Five patients required only the initial 300 mg dose of labetalol. Two patients required further therapy for satisfactory blood pressure control. Mean arterial pressure fell from 156 +/- 12 mm Hg to 123 +/- 14 mm Hg.
Clinical problems in follow-up of patients after conservative surgery and radiotherapy. Patients treated with conservative surgery and radiotherapy for early-stage breast carcinoma are at risk of developing an ipsilateral breast recurrence for a long period. Fortunately, few such patients present with an inoperable recurrence or simultaneous distant metastases. Salvage rates are high and may be improved by early detection. Although usually unambiguous, physical examination of the treated breast may reveal changes attributable to surgery and radiotherapy that can mimic a recurrent cancer. There also is substantial overlap in radiologic appearance between benign and malignant lesions. It may be necessary to perform a biopsy when there is a question of recurrence. Careful life-long follow-up of patients thus is a critical part of their care.
Urinary tract infection in women. Current role of single-dose therapy. Administration of a single dose of an antimicrobial agent is acceptable therapy for women with uncomplicated lower urinary tract infections. There is adequate information in the literature to support the clinical use of single-dose therapy, although there is still a need for further, well-designed, sufficiently large studies that compare single-dose therapy to abbreviated-course (3-day) and traditional (7- to 14-day) therapy.
Hoarseness as the sole presenting symptom of foramen magnum meningioma. Foramen magnum tumours are rare. They may present with bizarre symptoms and mimic many conditions. We report a presentation with the sole complaint of hoarseness, never previously described in the literature. Voice returned to normal after surgical removal of the foramen magnum meningioma.
Cryptic osteoid osteoma of the cranium: case report. Osteoid osteoma is an uncommon benign tumor of bone that rarely involves the cranium. If often causes local pain that is worse at night, characteristically relieved by aspirin, and does not correlate with the size of the lesion. The diagnosis depends on skull radiographs and computed tomography. This report describes a case in which radiographs showed nothing abnormal. The diagnosis and operative localization were accomplished with radionuclide bone scanning. Thus, the possibility of radiographically cryptic lesions must be considered in the evaluation of atypical head pain syndromes.