123rc/medical_text huggingface dataset:
Tissue changes around loose prostheses. A canine model to investigate the effects of an antiinflammatory agent. The aseptically loosened prosthesis provided a means for investigating the in vivo and in vitro activity of the cells associated with the loosening process in seven dogs. The cells were isolated and maintained in culture for sufficient periods of time so that their biologic activity could be studied as well as the effect of different agents added to the cells in vivo or in vitro. The biologic response as determined by interleukin-1 and prostaglandin E2 activity paralleled the roentgenographic appearance of loosening and the technetium images and observations made at the time of revision surgery. The correlation between clinical, roentgenographic, histologic, and biochemical loosening indicates that the canine model is suitable for investigating the mechanisms of prosthetic failure. A canine model permits the study of possible nonsurgical therapeutic interventions with the ultimate hope of stopping or slowing the loosening process.
Neuropeptide Y and neuron-specific enolase levels in benign and malignant pheochromocytomas. Neuron-specific enolase (NSE) is the isoform of enolase, a glycolytic enzyme found in the neuroendocrine system. Neuropeptide Y (NPY) is a peptide recently discovered in the peripheral and central nervous systems. Serum NSE and plasma NPY levels have been reported to be increased in some patients with pheochromocytoma. The authors evaluated whether the measurement of these molecules could help to discriminate between benign and malignant forms of pheochromocytoma. The NSE levels were normal in all patients with benign pheochromocytoma (n = 13) and elevated in one half of those with malignant pheochromocytoma (n = 13). Plasma NPY levels were on the average significantly higher in the malignant (177.1 +/- 38.9 pmol/l, n = 16) than in the benign forms of the disease (15.7 +/- 389 pmol/l, n = 24). However, there was no difference in the percentage of patients with elevated NPY levels. These results show that determination of serum NSE may be useful for distinguishing between malignant and benign pheochromocytoma; the measurement of plasma NPY is not useful for differentiating the two kinds of tumors.
Sexually transmitted diseases of the colon, rectum, and anus. The challenge of the nineties. During the past two decades, an explosive growth in both the prevalence and types of sexually transmitted diseases has occurred. Up to 55 percent of homosexual men with anorectal complaints have gonorrhea; 80 percent of the patients with syphilis are homosexuals. Chlamydia is found in 15 percent of asymptomatic homosexual men, and up to one third of homosexuals have active anorectal herpes simplex virus. In addition, a host of parasites, bacterial, viral, and protozoan are all rampant in the homosexual population. Furthermore, the global epidemic of AIDS has produced a plethora of colorectal manifestations. Acute cytomegalovirus ileocolitis is the most common indication for emergency abdominal surgery in the homosexual AIDS population. Along with cryptosporidia and isospora, the patient may present to the colorectal surgeon with bloody diarrhea and weight loss before the diagnosis of human immunodeficiency virus (HIV) disease. Other patients may present with colorectal Kaposi's sarcoma or anorectal lymphoma, and consequently will be found to have seropositivity for HIV. However, in addition to these protean manifestations, one third of patients with AIDS consult the colorectal surgeon with either condylomata acuminata, anorectal sepsis, or proctitis before the diagnosis of HIV disease. Although aggressive anorectal surgery is associated with reasonable surgical results in some asymptomatic HIV positive patients, the same procedures in AIDS (symptomatic HIV positive) patients will often be met with disastrous results. It is incumbent upon the surgeon, therefore, to recognize the manifestations of HIV disease and diagnose these conditions accordingly.
Lipolytic factors associated with murine and human cancer cachexia. We have identified a lipolytic factor in extracts of a cachexia-inducing murine carcinoma (MAC16) that shows characteristics of an acidic peptide and appears to be composed of three fractions of apparent molecular weights corresponding to 3 kd, 1.5 kd, and 0.7 kd, as determined by exclusion chromatography. Material with identical chromatographic and molecular weight characteristics was also present in the serum of patients with clinical cancer cachexia but absent from normal serum, even under conditions of starvation. The MAC16 lipid factor, when injected into animals bearing the non-cachexia-inducing tumor MAC13, was capable of inducing weight loss without a significant reduction in food intake. Similar lipolytic material, although in lower concentration, was also found in the MAC13 tumor extracts. These findings suggest that cachexia may arise from the enhanced expression of a lipolytic factor associated with tumor cells.
Does carotid restenosis predict an increased risk of late symptoms, stroke, or death? The identification of carotid restenosis as an unexpected late complication of carotid endarterectomy has prompted concerns regarding its importance as a source of new cerebral symptoms, stroke, and death. To investigate these concerns, we analyzed a consecutive series of 507 patients undergoing 566 carotid endarterectomies, each documented as technically satisfactory. Post-operative duplex Doppler examination data at 3 days, 1, 3, 6, 12 months, and annually thereafter in 484 arteries (85.5%) permitted classification of these arteries according to the most severe degree of postoperative stenosis: normal (n = 306); 1% to 19% (n = 89); 20% to 50% (n = 40); more than 50% (n = 49, including 8 occluded). The incidence of more than 50% restenosis was 14.5% in female and 7.7% in male patients (p = 0.003). Life table analyses to 10 years revealed a significantly greater life expectancy among those with restenosis (p = 0.05). Stroke was also less likely in patients with restenosis, although this difference did not reach statistical significance. When survival and stroke were both endpoints, the likelihood of patients with more than 50% restenosis remaining alive and stroke free was also greater than the less than 20% stenotic group (p = 0.03). Thus patients with carotid restenosis were less likely than patients with normal postoperative scans to have late symptoms, stroke, or early death.
The shoulder in multiple epiphyseal dysplasia. One hundred shoulders were assessed in 50 patients with multiple epiphyseal dysplasia, of which one-third were found to have bilateral symptoms. Two distinct clinical and radiological groups emerged. Those with minor epiphyseal abnormalities developed painful osteoarthritis in middle age, but retained shoulder movement until the secondary changes were advanced. Those with 'hatchet head' shoulders likewise became painful in the fifth and sixth decades but had minimal glenohumeral movement from an early stage.
Pharmacomechanical thrombolysis and angioplasty in the management of clotted hemodialysis grafts: early and late clinical results. The results of pharmacomechanical thrombolysis and angioplasty of 121 thrombosed hemodialysis grafts were reviewed. The initial pharmacomechanical method (used in 65 cases) employed clot maceration with hook-shaped catheters and clot lacing with highly concentrated urokinase. The current technique (used in 56 cases) consisted of pulsed-spray injection of urokinase into the clot. All fully treated grafts (117 cases) underwent complete or near-complete thrombolysis, and 93% remained patent after 1 day. Mean time for pulsed-spray lysis was 46 minutes +/- 21. One patient (less than 1%) had gastrointestinal bleeding and received a transfusion; minor complications occurred in 3% of patients. Primary and secondary graft patency rates for both methods at 1 year were 26% and 51%, respectively. While graft age and results of angioplasty did not influence future graft patency, shorter intervals between graft thromboses was predictive of earlier subsequent graft failure. Results suggest that pharmacomechanical thrombolysis and angioplasty provide rapid, consistent, and safe recanalization of clotted hemodialysis grafts and represent a promising additional therapeutic approach to long-term graft management.
Color Doppler diagnosis of mechanical prosthetic mitral regurgitation: usefulness of the flow convergence region proximal to the regurgitant orifice. In prosthetic or paravalvular prosthetic mitral regurgitation, transthoracic color Doppler flow mapping can sometimes fail to detect the regurgitant jet within the left atrium because of the shadowing by the prosthetic valve. To overcome this limitation, we assessed the utility of color Doppler visualization of the flow convergence region (FCR) proximal to the regurgitant orifice in 20 consecutive patients with mechanical prosthetic mitral regurgitation documented by surgery and cardiac catheterization (13 of 20 patients). In addition, we studied 33 patients with normally functioning mitral prostheses. Doppler studies were performed in the apical, subcostal, and parasternal long-axis views. An FCR was detected in 95% (19 of 20) of patients with prosthetic mitral regurgitation. A jet area in the left atrium was detected in 60% (12 of 20) of patients. In 18 of 19 patients with Doppler-detected FCR, the site of the leak was correctly identified by observing the location of the FCR. A trivial jet area was detected in eight patients with a normally functioning mitral prosthesis; in none was an FCR identified. Thus color Doppler visualization of the FCR proximal to the regurgitant orifice is superior to the jet area in the diagnosis of mechanical prosthetic mitral regurgitation. Moreover, FCR permits localization of the site of the leak with good accuracy.
Noninvasive diagnosis of right-sided extracardiac conduit obstruction by combined magnetic resonance imaging and continuous-wave Doppler echocardiography. Right-sided extracardiac conduits are frequently complicated by obstruction over time. We compared the utility of two-dimensional and Doppler echocardiography and magnetic resonance imaging in the diagnosis of postoperative right-sided obstruction with cardiac catheterization and angiography in 10 patients with xenograft or homograft conduits. Correlation (r = 0.95) between continuous-wave Doppler estimates and catheter pullback pressure gradients across the conduits was excellent. Echocardiography could only visualize five of 10 conduits in their entirety. Magnetic resonance imaging visualized all conduits and showed statistically significant (kappa = 0.58) agreement with angiography in the localization and estimation of severity of a variety of right-sided obstructions in these patients. However, flow voids created by the metallic ring around xenograft valves led to a false negative diagnosis of valvular stenosis in four patients when magnetic resonance imaging was used alone. Doppler studies correctly indicated obstruction in these patients. The combination of magnetic resonance imaging studies and continuous-wave Doppler echocardiography can be useful to noninvasively evaluate right-sided obstruction in postoperative patients with right-sided extracardiac conduits.
Sodium sensitive and sodium retaining hypertension. The differences between sodium sensitive and sodium retaining hypertension were theoretically considered using a water tank model of body fluid volume-blood pressure regulation. If an outlet valve is attached to a tank with a base area corresponding to the reciprocal of total peripheral resistance (TPR) and water is poured into this tank at a rate corresponding to the amount of Na+ intake, then equilibrium should be achieved at a certain water level, volume and output from the outlet, which represent mean arterial pressure (MAP), cardiac output (CO) and urinary Na+ excretion. The height of the outlet from the tank bottom and the size cross-sectional area, of the outlet correspond to the x-intercept and slope of the renal function (pressure-natriuresis) curve, respectively. In both nonsodium sensitive hypertension, due to the shift of the curve toward a higher blood pressure level (elevated height of the outlet) without change in the slope (size of the outlet), and sodium sensitive hypertension, due to the depressed slope of the curve (reduced outlet size), not only MAP (water level) but also CO (water volume) are increased, resulting in sodium retaining hypertension, if TPR (reciprocal of base area) remained unchanged, while CO is relatively unchanged, resulting in nonsodium retaining hypertension, if TPR is elevated. Thus, the MAP and its sensitivity to sodium intake is determined by the renal function curve. Since body fluid volume is determined by both the renal function curve and TPR, however, changes in TPR during the development of hypertension is a major factor in determining whether or not the body fluid volume has to change only a small amount or a large amount. Therefore, the sodium sensitivity of blood pressure and sodium retention must be considered separately.
Imaging bone tumors in the 1990s. Progress in bone tumor management has occurred as a result of cooperation among surgeons, oncologists, pathologists, and radiologists. During the 1990s radiologists will contribute to care of patients with bone tumors in major ways. Tumor detection and preliminary diagnosis will be accomplished by radiography. Tumor local extent will be assessed by magnetic resonance imaging (MRI) and to a lesser degree by computed tomography (CT). Distant spread of malignancy will be documented by radionuclide scintigraphy (skeleton) and by CT (lungs). The combined estimate of local extent and distant spread will assure adequate staging before definitive management decisions. Preoperative closed percutaneous biopsy for histologic diagnosis will be accomplished on an outpatient basis under fluoroscopic or CT guidance. Arteriography will be employed for delivery of local chemotherapy. Some combination of arteriography, MRI, and MR spectroscopy will be used to evaluate tumor response. After limb-salvage surgery, MRI will sequentially assess the tumor bed; bone scintigraphy and CT will detect skeletal and pulmonary metastases. The radiologist's role will undergo continuous redefinition.
Closure of a bronchopleural fistula with bronchoscopic instillation of tetracycline. Persistent bronchopleural fistulas (BPF) due to infection, trauma, or thoracic surgical procedures are often difficult to manage. We report a patient with fulminant Staphylococcus aureus pneumonia complicated by chronic BPF formation which prevented weaning from mechanical ventilation due to severe air leak. Fistula closure was obtained by instillation of tetracycline into the fistula via a fiberoptic bronchoscope using a balloon catheter and blood clot occlusion technique. This closed the BPF and allowed successful weaning from mechanical ventilation.
Utility of frozen-section evaluation of lymph nodes in the staging of bronchogenic carcinoma at mediastinoscopy and thoracotomy. We conducted a retrospective analysis of the utility of frozen-section diagnoses in determining lymph node status at mediastinoscopy in 122 consecutive patients with bronchogenic carcinoma. Thirty-five of 122 patients had one or more lymph nodes with frozen-section evaluation positive for metastatic carcinoma. Subsequent nodal sections not in the original frozen-section study revealed metastatic carcinoma in two additional patients. The false-negative rate was 1.6%. Sensitivity was 94.6%. Predictive value of negative frozen-section evaluation results was 97.7%. Because there were no false-positive frozen-section results, specificity and predictive value for positive results of frozen-section evaluation were 100%. The statuses of individual lymph nodes from these 122 patients were also evaluated. Six hundred twenty lymph nodes were sampled from the mediastinum at mediastinoscopy. Frozen-sections in 47 lymph nodes were positive. Subsequent nodal sections not in the original frozen-sections examination revealed metastatic carcinoma in four additional lymph nodes. The false-negative rate was 0.6%. Sensitivity was 92.2%. Predictive value of negative results from frozen-section evaluation was 99.3%. Because there were no false-positive frozen-section results, specificity and predictive value for positive results of frozen-section examination were 100%. We conclude that frozen-section evaluation of lymph nodes at mediastinoscopy reliably indicates lymph node status, thus enabling the physician to decide whether to proceed to thoracotomy. Thus staging of the carcinoma and definitive surgery can be accomplished during a single anesthetic procedure. Combining mediastinoscopy and thoracotomy with frozen-section diagnostic control also reduces both the length and cost of hospitalization.
Antihypertensive drugs and glucose metabolism: comparison between a diuretic, a beta-blocker and felodipine, a new calcium antagonist in subjects with arterial hypertension and diabetes. Felodipine, a new antihypertensive calcium antagonist, was compared with metoprolol, a beta-blocker, and hydrochlorothiazide, a diuretic, with respect to glucose tolerance in a randomized double-blind cross-over study consisting of 11 patients, of age range 50-70 years, who had developed diabetes during antihypertensive treatment. Each treatment period lasted for 10 weeks. The blood pressure was similar irrespective of treatment. Serum glucose levels during the oral glucose tolerance test were significantly lower when the patients were treated with felodipine than when they were taking hydrochlorothiazide. Serum insulin levels appeared to decrease at an earlier stage of the test when the patients were treated with felodipine, the calcium antagonist, than with the other two antihypertensive substances, which suggests that glucose tolerance is impaired to a lesser extent during treatment with the calcium antagonist. Glucose tolerance was never completely normalized with any of the drugs tested.
Gallbladder perforation: correlation of cholescintigraphic and sonographic findings with the Niemeier classification. We retrospectively analyzed the cholescintigrams and sonograms of 36 consecutive patients with gallbladder perforation to (a) determine the sensitivity of each for the preoperative detection of gallbladder perforation and (b) correlate the findings with the modified Niemeier classification. Cholescintigraphic criteria of perforation (free spill, pericholecystic hepatic activity, and scintigraphic gallstone ileus sign) were detected in 14 of 28 (50%) cases, while sonographic criteria of perforation (pericholecystic fluid or pneumobilia with gallstones) were present in 18% (4 of 22) of patients (p less than 0.05). Cholescintigraphic patterns of perforation associated with the Niemeier classification were: Type I (acute free perforation), 3 of 7 scans demonstrated free spill; Type II (subacute pericholecystic abscess), 9 of 19 scans showed pericholecystic activity; and Type III (chronic cholecystoenteric fistula), 1 of 3 scans showed a scintigraphic gallstone ileus. Thus, although cholescintigraphy appears superior to sonography, both modalities are relatively insensitive for the detection of gallbladder perforation.
Left ventricular fibroma: echocardiographic diagnosis and successful surgical excision in three cases. The management of three patients with left ventricular fibromas is outlined. All were asymptomatic children. Routine chest radiography suggested cardiac masses. M-mode and two-dimensional echocardiography were valuable adjuncts to conventional angiography in assessing these children. Electrocardiographic changes, present in all cases, were shown to regress postoperatively. We stress the importance of these noninvasive aids in the initial investigation and outline our operative methods of reconstruction.
Tongue ischemia from a soft-drink can: report of case. A young girl was brought to the emergency department because her tongue became entrapped while she was drinking from an aluminum soft-drink can. A dental drill was used to remove the can. The tongue was observed for 48 hours, during which an ischemic area recovered spontaneously.
In vitro and in vivo effects within the coronary sinus of nonarcing and arcing shocks using a new system of low-energy DC ablation. DC shocks within the coronary sinus have been abandoned because of the risk of cardiac rupture and tamponade. Catheter ablation using DC energy to electrodes straddling the ostium of the coronary sinus, when used clinically, has been reported to result in cardiac tamponade in as many as 16% of patients. A new system of energy delivery maximizes voltage while decreasing the undesirable effects caused by barotrauma. This system includes 1) a low-energy ablation power supply with a brief time-constant capacitive discharge that delivers up to 40 J and 3,000 V and 2) a low-energy ablation catheter with a contoured distal electrode. We performed in vitro and in vivo studies of this new system and compared arcing shocks with nonarcing shocks. Ablations were performed using unipolar distal shocks (D) and unipolar shocks to both electrodes made electrically common (P-D). In vitro studies were done in a large tank filled with physiological saline while recording voltage, current, and pressure. High-speed cinematography (32,000 frames/sec) of shocks of 10-40 J permitted detailed analysis of the vapor globe. Anodal shocks of less than 20 J showed no arcing or only minimal vapor globe formation. For D and P-D anodal shocks of 40 J, the diameters of the vapor globe were 31 and 22 mm, respectively, corresponding to pressure recordings of 11 and 4.9 atm. The pressure rise lasted less than 50 mu sec. In vivo studies involved 18 dogs that received nonarcing shocks (one to six shocks of 15 J) and 18 dogs that received arcing shocks (one to three shocks of 40 J). Each group was divided between D and P-D shocks; catheter ablation was performed at a mean +/- SEM distance of 2.94 +/- 0.92 cm within the coronary sinus. All dogs tolerated the procedure without cardiac rupture or tamponade. When killed 2-4 days later, the dogs had edema and hyperemia or hemorrhage in the area of the coronary sinus. We compared the effects of multiple (three to six) nonarcing shocks with the effects of one to three arcing shocks. Disruption or rupture of the coronary sinus within the epicardial fat space occurred in two of 12 dogs (17%) with multiple nonarcing shocks but in 13 of 18 dogs (72%) with arcing shocks (p less than 0.003). Occlusion of the coronary sinus occurred in two of 12 dogs (17%) with multiple nonarcing shocks and in nine of 18 dogs (50%) with arcing shocks (p less than 0.06).(ABSTRACT TRUNCATED AT 400 WORDS).
Chondrosarcoma of the jaws: clinical findings, histopathology, and treatment. Three cases of chondrosarcoma involving the jaws are presented, one in the maxilla and two in the mandible. The salient points of clinical presentation elucidated by this series of cases are that a widened periodontal ligament space is present in chondrosarcomas as well as in osteosarcomas, and that a slowly increasing diastema may be the earliest clinical sign. The most important lesson to be learned from the histopathology is that one should not accept a diagnosis of a benign cartilaginous tumor of the jaws. Treatment of these lesions should consist of wide surgical excision and consideration of adjunctive or palliative radiotherapy, especially in the maxilla. It should also be noted that recurrences may develop 10 to 20 years later, and follow-up should be lifelong.
Ear involvement in the yellow nail syndrome. Recognized features of the yellow nail syndrome include yellow nails, lymphedema, and pleural effusions. We report a patient with the additional feature of keratosis obturans, which may be a manifestation of this syndrome in the external ear.