123rc/medical_text huggingface dataset:
Granulocytic sarcoma presenting as an epidural mass with acute paraparesis in an aleukemic patient. Granulocytic sarcomas are rare tumors composed of granulocytic precursor cells. They are most commonly encountered in patients with acute myelogenous leukemias and myeloproliferative disorders in blast crisis. Rarely, patients presenting with granulocytic sarcoma show no evidence of acute leukemia. The authors report an aleukemic patient with acute paraparesis from an epidural granulocytic sarcoma. Only five such cases have been reported previously. Immunoperoxidase stain for lysozyme and chloroacetate esterase stain were used to prove the myeloid origin of the tumor cells.
Venous stasis and vein lumen changes during surgery The mechanisms underlying the development of postoperative deep vein thrombosis remain to be fully elucidated. Previous studies have suggested that peroperative venous distension may be a factor associated with venous thromboembolism. In this study we have obtained high resolution ultrasound images of gastrocnemius and posterior tibial veins in 62 patients undergoing a range of general surgical procedures. From these we determined the changes in vein diameter occurring during the operative procedures, in response to induction of anaesthesia, and after completion of surgery. Veins showed no evidence of dilatation in response to the induction of anaesthesia, but by the end of the operative procedure showed distension of 22-28 per cent. Distension was most prominent in the gastrocnemius veins, and lesser distension was observed in the posterior tibial veins. In a series of patients who received an infusion of 1 litre of saline in addition to basal requirements, distension was 57 per cent compared with 22 per cent in the corresponding control group. Intraoperative venous distension is associated with factors that lead to deep vein thrombosis and may be involved in the mechanisms which result in the commencement of deep vein thrombosis.
Intramuscular hemangioma in the oral region: report of three cases. The occurrence of intramuscular hemangioma in an intraoral or perioral localization is rare, and a thorough knowledge of these tumors is necessary for adequate diagnosis and treatment. Three cases are presented with discussion, and their histopathology and differential diagnosis are discussed. An adequate primary excision is necessary to avoid recurrence.
Post-traumatic epilepsy: cellular mechanisms and implications for treatment. Epilepsy complicates severe head trauma. Development of persistent seizures appears to correlate with the extent of trauma. Although early reports suggested that prophylactic administration of antiepileptic drugs would prevent epileptogenesis, controlled studies have failed to corroborate this assumption. Head trauma initiates a sequence of responses that includes altered blood flow and vasoregulation, disruption of the blood-brain barrier, increases in intracranial pressure, focal or diffuse ischemia, hemorrhage, inflammation, necrosis, and disruption of fiber tracts. The presence of an intracranial hematoma has a robust association with the development of post-traumatic epilepsy. Extravasation of blood is followed by hemolysis and deposition of heme-containing compounds into the neuropil, initiating a sequence of univalent redox reactions and generating various free radical species, including superoxides, hydroxyl radicals, peroxides, and perferryl ions. Free radicals initiate peroxidation reactions by hydrogen abstraction from methylene groups adjacent to double bonds of fatty acids and lipids within cellular membranes. Intrinsic enzymatic mechanisms for control of free radical reactions include activation of catalase, peroxidase, and superoxide dismutase. Steroids, proteins, and tocopherol also terminate peroxidative reactions. Tocopherol and selenium are effective in preventing tissue injury initiated by ferrous chloride and heme compounds. Treatment strategies for prevention or prophylaxis of post-traumatic epilepsy must await absolute knowledge of mechanisms. Antioxidants and chelators may be useful, given the speculation that peroxidative reactions may be an important component of brain injury responses. However, potential treatment strategies involving gamma-aminobutyric acid (GABA) agonists, NMDA receptor antagonists, and barbiturates need further scientific assessment.
Efficacy and safety of low- and high-dose sotalol versus propranolol in the prevention of supraventricular tachyarrhythmias early after coronary artery bypass operations. Supraventricular tachyarrhythmias are reported in up to 40% of patients early after coronary artery bypass graft operations. In a randomized study, we compared the efficacy and safety of the class III antiarrhythmic beta-blocking drug sotalol versus propranolol at low and high doses in the prevention of supraventricular tachyarrhythmias in 429 consecutive patients after coronary artery bypass graft operations. Patients with severely depressed left ventricular function and other contraindications for beta-blockers were excluded. From the fourth hour up to the sixth day after coronary artery bypass, 74 patients received low-dose sotalol (40 mg every 8 hours), 66 patients low-dose propranolol (10 mg every 6 hours), 133 patients high-dose sotalol (80 mg every 8 hours), and 156 patients high-dose propranolol (20 mg every 6 hours). Baseline characteristics were comparable in all groups. Supraventricular tachyarrhythmia was observed in 10 of 72 (13.9%) who received low-dose sotalol, 12 of 64 (18.8%) who received low-dose propranolol, 13 of 119 (10.9%) who received high-dose sotalol, and 19 of 139 (13.7%) who received high-dose propranolol (not significant). Drug-related adverse effects necessitating discontinuation of the drug occurred in four receiving low doses (2.9%) and in 31 receiving high doses (10.7%) (p less than 0.02). In conclusion, no medication was found to be superior, although supraventricular tachyarrhythmias tended to be less prevalent in patients treated with sotalol than in those treated with propranolol. Moreover, significantly fewer adverse effects were noted in both low-dose groups. Therefore, low-dose beta-blocking treatment, especially low-dose sotalol, seems preferable.
Return to work for persons with traumatic brain injury: a supported employment approach. Supported employment was used to place 41 persons into competitive employment during 30 months. All individuals had experienced severe head injuries; almost 70% of injuries were due to motor vehicle accidents. A mean of seven years had passed since injury for all referred clients, who had been unconscious a mean of 53 days. Only 36% of referred clients had achieved any competitive postinjury employment, compared with 91% of the same group who were competitively employed before injury. A job retention rate of 71% was reported, with most jobs in warehouse, clerical, and service-related occupations. A mean of 291 hours of job coaching was required to place and maintain all clients in supported employment.
Modulatory action of adenosine on gastric function and ethanol-induced mucosal damage in rats. This study examines the gastric effects of adenosine and its antagonist, theophylline, on secretory function, mucosal blood flow, and on ethanol-induced glandular mucosal damage in rats that were fasted for 24 hr before experimentation. The animals were anesthetized with sodium pentobarbitone (50 mg/kg intraperitoneal) and their tracheae cannulated. An ex vivo stomach chamber then was prepared. The luminal bathing solution was collected every 15 min and the concentrations of H+ and Na+ were determined by a pH autotitrator and an ionmeter, respectively. The glandular mucosal blood flow was measured by a laser Doppler flowmeter and the severity of lesions was determined by measuring the hemorrhagic areas. Adenosine administration (2.5 or 7.5 mg/kg, subcutaneous) markedly lowered the H+ and Na+ output but increased the secretory volume and mucosal blood flow in a dose-dependent manner. The same doses of the nucleoside also prevented ethanol-induced mucosal damage. These effects were prevented by pretreatment with theophylline (30 or 60 mg/kg, subcutaneous). Ethanol given alone significantly depressed the H+ and Na+ secretion. Both effects were not modified by adenosine treatment. However, the depressive action of ethanol on mucosal blood flow was prevented by adenosine. These findings indicate that adenosine modulates the physiological function of the stomach. It also directly activates the defensive mechanism of the stomach, which is partially mediated by the improvement of the gastric mucosal blood flow and an increase in the nonacid component of gastric secretion.
Early postoperative balloon coronary angioplasty for failed coronary artery bypass grafting. In a small number of patients, coronary artery bypass grafting (CABG) fails to relieve anginal symptoms. The usefulness of coronary angioplasty for the treatment of early (less than or equal to 90 days) recurrent ischemia after CABG was examined. Forty-five patients were treated from 2 to 90 days after CABG, including 8 patients studied emergently for prolonged ischemic symptoms. One-, 2- and 3-vessel native disease was found in 4, 10 and 31 patients, respectively. At the time of postoperative angiography, the major anatomic mechanism of recurrent ischemia was complete vein graft occlusion in 12 patients (27%), internal mammary artery occlusion in 3 (7%), vein graft stenoses in 13 (29%), internal mammary artery stenoses in 10 (22%), unbypassed disease in 4 (8%) and disease distal to the graft insertion site in 3 (7%). Angioplasty was successful at 91 of 98 sites (93%), including 95% of 41 lesions in native arteries, 89% of 46 lesions in vein grafts and 100% of 11 internal mammary artery lesions attempted. Complete revascularization was achieved in 84% of patients. There were 2 in-hospital deaths and 2 myocardial infarctions. Two additional patients underwent repeat CABG before discharge after uncomplicated but unsuccessful angioplasty. At late follow-up of the 43 survivors (mean 44 months), there were 4 deaths, 2 of which were noncardiac. Repeat CABG was required in only 3 patients and repeat angioplasty was performed in 10. Angina was absent or minimal in 35 patients; 17 patients were employed full time. Thus, percutaneous transluminal coronary angioplasty can relieve myocardial ischemia after unsuccessful CABG in the majority of patients.
Primary adenocarcinoma of the urinary bladder. A clinicopathologic analysis of 72 cases. Adenocarcinomas account for approximately 2% of primary epithelial malignancies of the urinary bladder. The clinicopathologic features of 72 cases treated at one institution are reported; 22 cases were evaluated immunohistochemically. Twenty-four tumors were urachal and 48 nonurachal. The cases were analyzed according to their stage at presentation, histologic type, and mucin staining; they were tested immunohistochemically to determine their reaction to carcinoembryonic antigen, Leu-M1, prostate-specific antigen, and prostatic acid phosphatase. Tumor stage was a highly significant predictor of outcome (P = 0.001). Nonurachal tumors tended to have a worse outcome than urachal, but the difference was not statistically significant (P = 0.07). Histologic type was not a significant predictor of outcome (P = 0.10). For adenocarcinoma of the urinary bladder, stage was the most significant predictive factor; separating urachal from nonurachal tumors was important, but mucin histochemistry and immunohistochemistry did not help in this distinction. On occasion, a few tumors may react with some polyclonal antibodies to prostate-specific antigen; thus these results must be interpreted with caution. In these instances, the possibility of using highly sensitive and specific monoclonal antibodies such as the one employed in this study should be considered.
Single-stage laryngotracheal reconstruction. The mainstay for repairing subglottic and tracheal stenosis has been the rib graft with prolonged stenting. A refinement of this treatment was the use of the anterior cricoid decompression (split). We present single-stage reconstruction of the airway as an additional refinement of the laryngotracheoplasty. This article describes the experience of two institutions with single-stage reconstruction and offers some observations on the principles of the technique.
Respiratory muscle strength and control of ventilation in patients with neuromuscular disease. To assess the relationship between respiratory mechanics and muscle strength and control of ventilation in patients with neuromuscular disease (NMD), we compared PImax and PEmax at RV, FRC and TLC, total respiratory elastance (Ers) with VT, TI, TT, VE, VT/TI, TI/TT, P.01, and P.01/(VT/TI) effective impedance in 21 patients with NMD and 21 healthy control (C) subjects, in seated position breathing room air. Ers in NMD patients was 79 percent higher than in the C subjects. While TI, TT, and VT in NMD were approximately half the corresponding C values, P.01 was 66 percent greater than in the C subjects (both p less than 0.001). NMD PImax and PEmax ranged from 37 to 52 percent of corresponding C values, respectively. Despite significant respiratory muscle weakness, only 7 of 16 patients demonstrated a PaCo2 greater than 45 mm Hg. Ventilatory output in NMD was modulated by respiratory mechanics as indicated by the increased P.01. In spite of muscle weakness, central drive in patients with NMD is not decreased, and in fact, is often increased. VE is not an accurate measure of central drive because of abnormal intrinsic respiratory mechanics and the effects of conscious responses or reflexes.
Secondary femoral-distal bypass. Thirty-nine secondary femoral-distal (femorotibial and femoroperoneal) bypasses were reviewed and compared to 89 primary femoral-distal bypasses (done during the same time period) to investigate the efficacy of secondary femoral-distal bypass. Graft patency at 2 years by life table analysis was similar in both groups (38% primary group vs 36% secondary group). However, limb salvage was significantly less in the secondary group (52% vs 68% at 2 years, p less than 0.05). This decrease was primarily due to poorer limb salvage using composite grafts (prosthetic/vein) compared to vein grafts in patients who underwent secondary femoral-distal bypasses (37% vs 76% at 2 years, p less than 0.05). Postoperative wound infections and mortality were similar in both groups. Thus, femoral-distal bypass after failure of a previous infrainguinal reconstruction offers good long-term limb salvage with acceptable surgical risk when autologous vein is available for use as the arterial conduit.
Aetiology of pancreatic cancer Curative surgery is possible in only a small minority of patients with pancreatic cancer and, to date, responses to chemotherapy and radiotherapy have been disappointing. To make any impact on the incidence of the disease a clearer understanding of its aetiology is required. This review explores present knowledge of the aetiology and epidemiology of pancreatic cancer.
Influence of hypoxia on adrenergic modulation of triggered activity in isolated adult canine myocytes. Although findings from several reports suggest that nonreentrant or focal mechanisms contribute to the genesis of arrhythmias during early ischemia, the contribution of triggered activity arising from early or delayed afterdepolarizations has not been resolved. We have previously demonstrated that beta- but not alpha-adrenergic stimulation induces afterdepolarizations and triggered activity in isolated normoxic myocytes. In the present study, the influence of the extent of cellular derangements as well as increases in [K+]o on alpha- and beta-adrenergic-mediated afterdepolarizations and triggered activity was evaluated. Adult canine myocytes were exposed to one of the following experimental conditions with simultaneous intracellular transmembrane action potential recordings: 1) low PO2 (less than 10 mm Hg, obtained using a specially designed hypoxic chamber) and low (6.8) pH; 2) low PO2, low pH, and high extracellular potassium ([K+]o) (10 mM); or 3) severe metabolic inhibition with cyanide (10(-6) M). Cells from each group were superfused with either the alpha-agonist phenylephrine (10(-5) or 10(-7) M, with 10(-5) M nadolol) or the beta-agonist isoproterenol (10(-6) M). Moderate changes in the action potentials were observed under conditions 1 and 2 (moderate hypoxia), whereas marked but reversible changes were observed with cyanide (severe metabolic inhibition). During moderate hypoxia in normal [K+]o, delayed afterdepolarizations or triggered activity were elicited by both alpha- (12 of 13 cells) and beta-adrenergic (five of five cells) stimulation. Increasing [K+]o during moderate hypoxia completely abolished the afterdepolarizations induced by alpha-adrenergic stimulation and prevented the occurrence of triggered activity. In contrast, the influence of beta-adrenergic stimulation was only attenuated by an increase in [K+]o. Exposure to cyanide completely prevented the induction of afterdepolarizations and triggered activity by both alpha- and beta-adrenergic stimulation. Our findings indicate that moderate hypoxia in normal [K+]o is associated with the development of adrenergic-mediated afterdepolarizations and triggered activity. In contrast, accumulation of [K+]o or severe impairment of cellular metabolism is accompanied by inhibition of adrenergic-mediated afterdepolarizations and triggered activity.
Vagal schwannoma associated with syncopal attacks and postural hypotension: a case report. A case of vagal schwannoma in the cerebellomedullary angle is reported. Preoperatively, the patient had paroxysmal episodes of postural hypotension with syncope. After total removal of the vagal tumor, her systemic blood pressure returned to normal.
Improved access to lesions of the central skull base by mobilization of the zygoma: experience with 54 cases. Improved access to lesions at the medial end of the sphenoid wing or in the interpeduncular cistern after mobilization of the zygoma has been a subject of growing interest in recent years. This study describes the operative technique we have adopted and records our experience with 55 operations in 54 patients who underwent the procedure in the past 3 years. Seven patients had vascular lesions, 44 had tumors, and 3 had miscellaneous lesions. The majority of the tumors were medial meningiomas, and particular note is made of those arising from the cavernous sinus with respect to their resectability. Sixteen of these tumors were encountered, and total excision was possible in 11 cases. Access to the infratemporal fossa is facilitated, and in 2 cases we were able to excise completely trigeminal neuromas that had extended there. The extra maneuver adds little to the overall operating time, and complications relating to it are uncommon, mild in degree, and usually self-limiting. We conclude that the operation is extremely valuable in appropriate circumstances.
Cortical atrophy and cognitive performance in infantile nephropathic cystinosis. A group of children and adolescents with infantile nephropathic cystinosis underwent cognitive testing and were examined for cortical atrophy using magnetic resonance imaging or computed tomography. Ten of 11 patients demonstrated cortical atrophy. A consistent pattern of lower cognitive performance was found in patients with greater atrophy; however, only the relationship between atrophy and short-term memory approached statistical significance. In addition, evidence for greater impairment of visual memory than of other cognitive functions was observed. This latter observation did not appear to be related to the degree of atrophy.
Melanosis of the esophagus. An endoscopic, histochemical, and ultrastructural study. Endoscopic, histological, and ultrastructural features of 21 cases of esophageal melanosis are described. These cases were detected during 1000 consecutive routine upper gastrointestinal endoscopies. Staining characteristics and ultrastructure of the pigment contained in the endoscopically visible lesions were found to be similar to those of true melanin.
Immunopathological response to loose cementless acetabular components. The membranes surrounding seven loose cementless acetabular implants were shown to contain polyethylene particles, birefringent in polarised light. Three of these implants were made of titanium alloy and the membranes around these contained titanium particles as well. There was no metallosis around the four implants made of chromium-cobalt-steel alloy. Both titanium and polyethylene particles caused migration, adherence and phagocytosis of CD11b-positive, peroxidase-negative macrophages. There were no histological signs of activation of the specific immune response; neither interleukin-2 receptor-positive activated T cells nor PCA-1 plasmablasts/plasma cells were present in the tissues. In cases of simple loosening, resident mesenchymal fibroblast-like cells were active. In aggressive granulomatosis, there were many macrophages and multinucleated giant cells but little fibroblast reaction. The clinical relevance of the findings is that the use of cementless prostheses is not a guarantee against adverse tissue reactions.
Hemolysis due to branch pulmonary stenosis after the arterial switch procedure. An infant with d-transposition of the great arteries underwent arterial switch operation using the modified Jatene technique. Severe bilateral branch pulmonary artery stenosis and mechanical hemolysis subsequently developed. The hemolysis resolved after surgical repair of the stenotic arteries. Probable causes are discussed.
Inflammatory abdominal aortic aneurysm masquerading as occlusion of the inferior vena cava. Inflammatory aneurysms are an uncommon disorder that represent between 5% and 10% of abdominal aortic aneurysms. Their presentation is often variable and may include pain and obstruction of adjacent anatomic structures. This report describes a 68-year-old man who sought treatment after insidious onset of progressive bilateral lower extremity edema over a 6-month period. Noninvasive studies were suggestive of bilateral iliac vein occlusion, and a venogram showed a nearly obstructed vena cava from external compression. A CT scan showed a thick-walled infrarenal abdominal aneurysm. At exploration an inflammatory abdominal aortic aneurysm was found. Because of the presence of dense inflammatory changes surrounding the aneurysm and extending into the pelvis, the surgical procedure of choice was an aortobifemoral bypass graft done with Dacron. The aneurysmal wall was debrided from the vena cava. His postoperative course was uneventful, his edema resolved, and follow-up noninvasive studies were normal. Postoperative venography showed resolution of the extrinsic compression of the vena cava.
Catabolic effects of high-dose corticosteroids persist despite therapeutic benefit in rheumatoid arthritis. Although corticosteroids (CS) cause nitrogen wasting in healthy humans, it is not known whether the salutary antiinflammatory and appetite-stimulating effects of CS in inflammatory diseases mitigate this effect. We measured nitrogen balance before, during, and after 3 d of high-dose methylprednisolone therapy in nine patients with flare-ups of rheumatoid arthritis. There was evidence of preexisting somatic protein and fat depletion in seven of nine subjects. Patients were allowed to eat freely on a metabolic ward. Nitrogen balances were -0.89 +/- 1.38 g/d (means +/- SEM) before CS therapy, -5.77 +/- 1.30 g/d during therapy (P less than 0.001), and -3.54 +/- 1.38 g/d after therapy (P less than 0.01) despite increased energy and nitrogen intake and clinical resolution of inflammation during and after the pulse therapy. We conclude that patients with rheumatoid arthritis are often cachectic and high-dose CS cause nitrogen wasting in these patients despite an antiinflammatory and appetite-stimulatory benefit.