123rc/medical_text huggingface dataset:
Nuclear shape as a prognostic discriminant in colorectal carcinoma. In search for a more reliable prognostic discriminant, a retrospective analysis of 100 cases of colorectal carcinoma having undergone curative resection and followed for at least 5 years were assessed by nuclear morphometry. Each case was staged according to the Dukes' classification as well as graded histologically. For all patients in this series, the perimeter, area, and nuclear shape factor of 50 interphase nuclei were determined for each carcinoma. The information was obtained through the use of an image analysis system by tracing the nuclear profiles (magnification 1000x) as digitized on a video screen. The nuclear shape factor was defined as the degree of circularity of the nucleus, a perfect circle recorded as 1.0. A nuclear shape factor greater than 0.84 was associated with poor outcome. Multiple regression models showed that the single nuclear parameter of the shape factor was the most highly significant predictor of survival (P less than 0.0001). This variable remained highly significant even when corrected for sex, age, histologic grade, and Dukes' classification. These findings indicate that a nuclear shape factor greater than or equal to 0.84 as determined by nuclear morphometry is an independent morphometric nuclear variable of great importance in the prognosis of large bowel carcinoma.
Impairment of the myocardial ultrastructure and changes of the cytoskeleton in dilated cardiomyopathy. This study was designed to determine the morphological correlate of chronic heart failure. Myocardial tissue from eight patients undergoing transplantation surgery because of end-stage dilated cardiomyopathy was investigated by electron microscopy and immunocytochemistry using monoclonal antibodies against elements of the cytoskeleton: desmin, tubulin, vinculin, and vimentin. The tissue showed hypertrophy, atrophy of myocytes, and an increased amount of fibrosis. Ultrastructural changes consisted of enlargement and varying shape of nuclei, numerous very small mitochondria, proliferation of T tubules, and accumulation of lipid droplets and glycogen. The most obvious ultrastructural alteration was the decrease of myofilaments, ranging from rarefication to complete absence of sarcomeres in cells filled with unspecified cytoplasm. Immunocytochemistry showed that desmin was localized at the Z lines. In diseased myocardium, the amount of desmin was increased, but it was disorderly arranged. Tubulin formed a fine network throughout the myocytes and was significantly increased in cardiomyopathic hearts. Vinculin, a protein closely associated with the cytoskeleton, occurred not only at the sarcolemma and the intercalated disc but also within the myocardial cells. Ultrastructural changes and alterations of the cytoskeleton were severe in about one third of all cells. About one third of all cells showed moderately severe changes, and the remaining cells were normal. Vimentin was present in the interstitial cells and was increased in relation to the increase of fibrosis. We conclude that the increase of fibrosis, the degeneration of hypertrophied myocardial cells, and the alterations of the cytoskeleton are the morphological correlates of reduced myocardial function in chronic heart failure.
Effects of the calcium antagonist nilvadipine on focal cerebral ischemia in spontaneously hypertensive rats. We studied the efficacy of preischemic and postischemic systemic treatment with a new calcium antagonist nilvadipine in a permanent focal cerebral ischemia model of spontaneously hypertensive rats. Rats that underwent microsurgical middle cerebral artery occlusion were blindly assigned to a single intraperitoneal injection of nilvadipine (0.32 mg/kg) or the same amount of polyethylene glycol either 15 minutes before, immediately after, 1 hour after, or 3 hours after occlusion of the left middle cerebral artery. Neurologic conditions of rats were closely examined, and rats were killed 24 hours later. Removed brains were sliced coronally, stained with triphenyltetrazolium chloride, and the size of infarct was determined. Although no neurologic improvements were observed in the treated rats, the area of infarcts was significantly reduced in the groups treated before, immediately after, and 1 hour after occlusion of the middle cerebral artery. Treatment started 3 hours after occlusion was ineffective.
Early afterdepolarizations and triggered activity in rabbit cardiac Purkinje fibers recovering from ischemic-like conditions. Role of acidosis. BACKGROUND. The mechanisms underlying repetitive activity during reperfusion of ischemic myocardium are thought to include triggered responses elicited at short pacing cycle lengths. The potential to generate repetitive responses at longer pacing cycle lengths under similar conditions, however, has not been explored. Thus, the present study examined the role of cycle length on the cellular electrical changes produced during recovery from ischemic-like conditions and identified the major component precipitating nondriven, repetitive activity. METHODS AND RESULTS. Transmembrane potentials were recorded in vitro from isolated rabbit Purkinje fibers exposed to hypoxia (defined as PO2 less than 30 mm Hg, high [K+]o, and zero glucose) plus lactic acidosis (pH 6.7) for 45 minutes and during recovery in normal Tyrode's solution (pH 7.4). Compared with control, action potential duration (90% repolarization) during recovery increased transiently by 40.9 +/- 11.8 and 241.0 +/- 51.1 msec at respective basic cycle lengths of 1,000 and 3,000 msec (both p less than 0.005). In 81% of preparations, action potential prolongation was accompanied by early afterdepolarizations and triggered activity generated from low (positive to -40 mV) or high (negative to -40 mV) membrane potentials. In 62% of experiments, brief periods of abnormal automaticity also occurred. Triggered responses were 1) unaffected by 1 microM ryanodine, 2) abolished by pacing at short basic cycle lengths or by exposing tissues to 2.5 micrograms/ml lidocaine, and 3) more easily induced at long basic cycle lengths or by superfusing 2.5 micrograms/ml quinidine. When tissues were conditioned with hypoxia alone (pH 7.4), action potential prolongation on recovery was comparatively small, and nondriven responses did not develop. Conversely, addition of 10-20 microM amiloride to the hypoxic, acidic test solution augmented recovery-induced action potential prolongation. CONCLUSIONS. We conclude that acidosis, as a component of ischemia, plus slow pacing frequencies may mediate the genesis of early afterdepolarizations and triggered activity in Purkinje fibers on recovery, long after extracellular pH has been restored to normal. These data may have clinical relevance to the mechanisms of reperfusion arrhythmias in the intact human heart.
Postpneumonectomy syndrome after left lung resection. A female infant with a right-sided aortic arch and ligamentum arteriosum underwent a left pneumonectomy for perinatal interstitial emphysema. Radiographic, bronchoscopic, and surgical evidence of compression of the right bronchial tree by the aorta, ligamentum arteriosum, right pulmonary artery, and thoracic spine subsequently developed. This report documents a rare example of postpneumonectomy syndrome following left lung resection.
Therapeutic cardiac catheterization in children Cardiac catheterization, once the mainstay of diagnosis in children with congenital heart disease, has become a therapeutic modality for many conditions. Balloon dilatation can now open stenotic valves and vessels, coils and umbrellas can now close unwanted communications, and emboli can be withdrawn without surgical intervention.
Pain management in the orthopedic patient. Pain is a familiar phenomenon to all orthopedic nurses. As Dunwoody said, "Few things we do for patients are more fundamental to the quality of life than relieving pain." We as orthopedic nurses are in a position to contribute to the positive management of pain by using a comprehensive approach to pain management that involves the participation of the patient. We need to believe the patient's pain, try new approaches, and help our patients achieve pain relief.
Coronary dynamics and mental arithmetic stress in humans. Incidence and mechanisms of psychological stress-induced myocardial ischemia were investigated in a population of 63 patients using mental arithmetic. Fifty subjects (group 1) were selected as a consecutive population of ischemic patients with electrocardiographic documentation of ischemia at rest, on effort, or both. Mental arithmetic induced increases in heart rate, blood pressure, and rate-pressure product in all patients. Transient ischemic electrocardiographic changes occurred in 22 patients (44%; positive mental arithmetic), the majority of whom had both resting and exercise angina. In negative mental arithmetic tests, peak rate-pressure product was always lower than that achieved during exercise (mean +/- SD, 11.9 +/- 3 versus 21.3 +/- 5, p less than 0.01). Of the 22 patients with positive mental arithmetic tests, ischemia occurred in only six, at a rate-pressure product equal to or more than the one achieved during exercise (21.1 +/- 5 versus 19.4 +/- 4, p less than 0.01), suggesting an increase in myocardial O2 demand exceeding the limited increase in flow; in the remaining 16 patients, rate-pressure product values were significantly lower (14.8 +/- 3 versus 22.7 +/- 6, p less than 0.01), suggesting a primary reduction in coronary blood flow that is probably related to an increase in coronary tone. To assess the possible site of such a vasoconstriction, the effect of mental arithmetic on large coronary artery diameter was tested in 13 additional unselected patients (group 2) undergoing coronary angiography for a chest pain syndrome.
Two cases of adult T-cell leukemia associated with acute pancreatitis due to hypercalcemia. We report two cases of adult T-cell leukemia associated with acute pancreatitis and hypercalcemia. After sudden onset of epigastralgia, acute pancreatitis and hypercalcemia were found in both patients. There were no diseases that could explain the acute pancreatitis except for hypercalcemia probably due to adult T-cell leukemia. Thus we considered that hypercalcemia due to adult T-cell leukemia had led to acute pancreatitis. This is the first report of such a complication in adult T-cell leukemia.
Nitrous oxide does not alter infarct volume in rats undergoing reversible middle cerebral artery occlusion. This experiment was designed to determine if nitrous oxide alters neurologic and pathologic outcome from temporary focal cerebral ischemia in spontaneously hypertensive rats deeply anesthetized with a barbiturate. Two groups of rats were given intravenous methohexital such that a stable EEG pattern of burst suppression was achieved. In one group of rats (n = 11), the lungs were mechanically ventilated with 70% N2O/30% O2, and in the other group (n = 10), ventilation was done with 70% nitrogen/30% O2. The middle cerebral artery was then occluded for 2 h, during which time mean arterial pressure, blood gases, hematocrit, plasma glucose, and head temperature were held constant between groups. The total doses of methohexital administered were similar in both groups as were the plasma methohexital concentrations immediately prior to onset of ischemia. After reperfusion of the middle cerebral artery, the animals were allowed to awaken. Neurologic evaluations were performed prior to ischemia and at 24 and 96 h postischemia. Cerebral infarct volume was measured at 96 h postischemia using triphenyl tetrazolium chloride staining and computer imaging techniques. There were no neurologic differences between the N2O and nitrogen groups at any experimental interval although both groups exhibited deficits at both 24 and 96 h postischemia relative to preischemic values. The two groups also had nearly identical cerebral infarct volumes (N2O = 231 +/- 97 mm3; nitrogen = 226 +/- 75 mm3; mean +/- SD).
Glucocorticoid-induced muscle atrophy prevention by exercise in fast-twitch fibers. Exercise has been shown to be effective in preventing glucocorticoid-induced atrophy in muscles containing high proportions of type II or fast-twitch fibers. This investigation was undertaken to further evaluate this response in type IIa and IIb fibers, determined by histochemical staining for myofibrillar adenosinetriphosphatase with alkaline and acid preincubation. Steroid [cortisol acetate (CA), 100 mg/kg body wt] and exercise (running 90 min/day, 29 m/min) treatments were initiated simultaneously for 11 consecutive days in female rats. Fiber distribution and area measurements were performed in a deep and superficial region of plantaris muscle. The exercise regimen spared approximately 40% of the CA-induced plantaris muscle atrophy. In the deep region, the fiber population, which contained approximately 13% type I (slow-twitch), 24% type IIa, and 63% IIb fibers, was not affected by either treatment. In the superficial section, which consisted solely of type II fibers, the proportion of type IIa fibers was higher (27 vs. 9%, P less than 0.01) in the steroid- than in the vehicle-treated groups. Within each region, type IIa fibers were less susceptible to atrophy than type IIb fibers, and within each fiber type, the deep region had less atrophy than the superficial region. Type I fibers were unchanged by steroid treatment. For type IIa fibers, exercise prevented 100% of the atrophy in the deep region and 50% in the superficial region. For type IIb fibers, the activity spared 67 and 40% of the atrophy in these same regions, respectively. These results show that glucocorticoids are capable of changing the myosin phenotype.
Duplex Doppler examination of a perinephric abscess in a renal transplant. Perinephric abscess has no characteristic ultrasonic appearance or location. Differentiation from urinoma, lymphocele, or hematoma depends on clinical and laboratory findings. Therapy consists of percutaneous catheter drainage, surgical drainage, and antibiotic therapy. Acute rejection is the most common cause of decreased diastolic flow during the immediate postoperative period. Acute tubular necrosis does not usually alter blood flow unless it is severe. Duplex doppler ultrasonic assessment of the renal transplant during the immediate postoperative period may provide a valuable baseline for comparison if complications develop. Baseline and follow-up ultrasonography to evaluate diastolic flow can help determine whether a posttransplant patient should receive emergency or conservative therapy for complications.
Effect of prostaglandin E in multiple experimental models: V. Effect on tumor/host interaction. Prostaglandin E (PGE) has long been incriminated as a cause of the immunosuppression seen in cancer patients and for the increased rates of tumor growth due to the impairment of the immunologic response to the tumor. We have investigated the effect of PGE on tumor-host interaction by utilizing a parenterally administered long-acting PGE derivative, 16,16-dimethyl-prostaglandin E (dPGE). Administration of dPGE was found to decrease the rate of tumor growth but at a cost of decreasing tumor-free body mass. The dPGE did not alter resting metabolic rates but did alter some parts of brain dopamine metabolism and significantly decreased the serum level of multiple amino acids. In conclusion, elevated PGE levels may significantly alter metabolism in tumor patients.
Necrotizing angiopathy presenting with multifocal conduction blocks. We describe conduction block as an unusual electrophysiologic manifestation in a patient with necrotizing angiopathy. The patient developed subacute symptoms over a 1-month period consisting of progressive pain, tingling, and weakness of the lower extremities. Physical examination revealed a pattern consistent with a polyneuropathy. Electrodiagnostic studies provided evidence of a conduction block in the left ulnar nerve. Pathologic studies confirmed the process to be a necrotizing angiopathy. This report establishes the role of conduction block in human nerve ischemia.
Community hospital carotid endarterectomy in patients over age 75. We compared the prevalence of stroke and death in 133 patients aged 75 and older in whom 170 carotid endarterectomies were performed with that in 501 patients less than age 75 in whom 640 carotid endarterectomies were performed. There were three strokes (2%) in patients aged 75 and older and nine strokes (1%) in younger patients (p = 0.7). There were 8 deaths (5%) in patients aged 75 and older and 14 deaths (2%) in younger patients (p = 0.1). After controlling for the possible confounding effects of diabetes, prior stroke, history of angina, prior carotid artery disease, previous vascular surgery, history of myocardial infarction, preoperative hypertension requiring medication, and female gender, a logistic regression model showed that patients aged 75 and older were no more likely to have a stroke or death than patients under age 75. We conclude that age alone is not a contraindication to the safe performance of carotid endarterectomy in the community hospital.
Clostridial bacteremia in cancer patients. A 12-year experience. Over 12 years, 136 episodes of bacteremia caused by clostridial species were documented. Eighty-three were monomicrobial, and 53 were polymicrobial. Gastrointestinal, genitourinary carcinomas, and acute leukemia were the most common underlying malignancies. Septic shock occurred in 29% of monomicrobial bacteremias and 45% of polymicrobial bacteremias and was associated with a high mortality rate. Acute hemolysis, gas gangrene, and diffuse spreading cellulitis occurred infrequently but were associated with a 100% fatality rate. Many infections caused by Clostridium perfringens and C. septicum were associated with abdominal disease. The most commonly isolated organism was C. perfringens, followed by C. septicum and C. sporogenes. Overall survival was 58%, but it was 66% for monomicrobial episodes and 45% for polymicrobial infections. All of the patients with bacteremia due to an aerobic gram-negative bacillus in addition to the clostridial species died of their infection. The most effective antibiotics were clindamycin, penicillin, metronidazole, and moxalactam. Surgical drainage of abscesses was an important component of therapy.
Severe hemorrhagic radiation proctitis advancing to gradual cessation with hyperbaric oxygen. We report a case of a male patient suffering from a severe hemorrhagic radiation proctitis which gradually ceased with hyperbaric oxygen. We discuss the mechanisms of chronic radiation injury and the effect of the hyperbaric oxygen. This therapy is proposed as an alternative to surgical intervention for this abnormality.
Transcranial electrical stimulation with high frequency intermittent current (Limoge's) potentiates opiate-induced analgesia: blind studies. Transcutaneous cranial electrical stimulation (TCES) with high frequency (166 kHz) intermittent current (100 Hz: Limoge current) has been used for several years in cardiac, thoracic, abdominal, urological and micro-surgery. The main benefits are a reduced requirement for analgesic drugs, especially opiates, and a long-lasting postoperative analgesia. We have confirmed these clinical observations in rats using the tail-flick latency (TFL) test to measure pain threshold. TCES was not found to modify the pain threshold in drug-free rats, but it potentiated morphine-induced analgesia (systemic injection). To obtain a maximal effect, the stimulation must be initiated 3 h before the drug injection and be maintained throughout the duration of its pharmacological action. TCES potentitation was found to depend on the dose of the drug, the intensity of the current and the polarity of electrodes. These findings were confirmed by blind tests of the efficiency of TCES on several opiate analgesic drugs currently used in human surgery (morphine, fentanyl, alfentanil and dextromoramide). The analgesic effect of these 4 opiates (TFL as % of baseline without or with TCES) were respectively: 174%, 306%; 176%, 336%; 160%, 215%; and 267%, 392%. The results were obtained not only after systemic opiate treatment, but also after intracerebroventricular injection of morphine (10 micrograms; analgesic effect 152%, 207% with TCES) suggesting that TCES potentiation of opiate-induced analgesia is centrally mediated.
Effects of prostaglandin E1 in postoperative surgical patients with circulatory deficiency. Hemodynamic and oxygen transport effects of PGE1 were observed in the early postoperative period before development of ARDS in two series of general surgical patients with circulatory deficiencies. The first was a series of 19 studies in 18 patients, the second was a placebo-controlled series of 20 patients (ten received PGE1 and ten received a placebo). In the first series, PGE1 was given as a trial of therapy after fluid therapy to pulmonary wedge pressures greater than 15 mm Hg failed to correct satisfactorily circulatory and metabolic functions. There were two deaths in the placebo group and none in the PGE1 group. Previous studies indicated that PGE1 disaggregates platelets and reduces local vasoconstriction in pulmonary circulation; this study suggests that PGE1 improves tissue perfusion of systemic circulation. After fluid therapy to PAOP greater than 15 mm Hg fails to restore circulatory function to optimal values. PGE1 should be considered as ancillary therapy in critically ill postoperative patients.
Percutaneous transluminal coronary angioplasty of anomalous right coronary artery. Coronary angioplasty of tortuous anomalous coronary arteries can be technically challenging. We describe a successful percutaneous transluminal coronary angioplasty (PTCA) of an anomalous right coronary artery after a failed previous attempt. The anatomic limitations of anomalous right coronary arteries and technical considerations for PTCA are discussed.
Chronic postoperative endophthalmitis associated with Actinomyces species. Actinomyces species, gram-positive, non-spore-forming anaerobic bacilli were isolated from intraocular fluid obtained from four otherwise healthy patients with a delayed onset of postoperative endophthalmitis. One patient had a mixed anaerobic infection with recovery of both Actinomyces israelii and Propionibacterium acnes. In all four patients, early postoperative visual acuity was good but was eventually markedly reduced by intraocular inflammation that was first observed between 21 days and 4 months following uneventful extracapsular cataract extraction and posterior chamber intraocular lens implantation. Inflammation was characterized by anterior segment and vitreous cellular debris in all cases. All eyes responded to therapy that included intraocular, topical, and systemic antibiotics as well as pars plana vitrectomy and partial iridectomy. These cases further illustrate the need for microbiologic investigation, including anaerobic cultures, in all cases of chronic postoperative inflammation following extracapsular cataract extraction, regardless of the time of onset.